WO2015015386A1

WO2015015386A1 - Two-dimensional graphene-based porous polymer and the preparation thereof

Info

Publication number: WO2015015386A1
Application number: PCT/IB2014/063405
Authority: WO
Inventors: Shyam Sundar Venkataraman; Xinliang Feng; Xiaodong Zhuang; Fan Zhang; Dongqing Wu
Original assignee: Basf Se; Basf (China) Company Limited
Priority date: 2013-08-01
Filing date: 2014-07-25
Publication date: 2015-02-05
Also published as: TW201522084A

Abstract

Sandwich-type, two-dimensional graphene-based porous polymer has been successfully synthesized via a graphene-mediated Sonogashira-Hagihara coupling of an alkyne monomer with a halogen-containing monomer and a condensation reaction between melamine and a dialdehyde monomer. The two-dimensional conjugated microporous polymer has high surface area of up to 888 m²g-¹ and fluorescence quenching phenomena compared with corresponding polymer network not based on a graphene template. Upon thermal pyrolysis, S- and/or N-doped two-dimensional porous carbons can be readily fabricated in a template-free manner. Such graphene-based two-dimensional porous carbon exhibits high heteroatom content with large surface area, and excellent supercapacitor performance.

Description

Two-dimensional Graphene-based Porous Polymer and the preparation thereof

FIELD OF THE INVENTION

The present invention relates to a porous polymer. In particular, the present invention re- lates to a sandwich-type two-dimensional graphene-based porous polymer, and more particular, the present invention relates to a sandwich-type two-dimensional graphene-based micro-porous polymer, to the process for producing the same, and to the use thereof.

BACKGROUND OF THE INVENTION

Porous polymers with porosity at the nano-scale have attracted tremendous attention due to their porous features associated with prominent physical properties and potential applications, such as in light harvesting, sensing, gas separation and storage, catalysis, and energy storage and conversion. There are several classes of micro-/meso-porous polymers, such as hypercrosslinked polymers (HCPs), polymers of intrinsic microporosity (PI Ms), and covalent organic frameworks (COFs). Porous polymers can be also classified according to their structural conformations as amorphous-(such as HCPs and PI Ms) or crystalline-type (such as COFs) materials. Conjugated microporous polymers (CPPs) represent one of the fastest developing types of porous materials not only because of their high efficiency for conventional metal- catalyzed polymerization techniques and the availability of a large number of commercially available functional monomers but also due to their controllable and adaptable physical properties. Unlike COFs, CPPs are formed under kinetic control, and thus are amorphous and show no long-range structural order. For this reason, most of the previous work on CPPs has been focused on developing new chemical strategies and tuning the pore size distribution and surface area of these polymers by varying the length of the organic linkers rather than through morphology control. Very recently, efforts have been made to synthesize CPPs with controlled nanostructures, such as quasi-zero-dimensional microspheres, and one-dimensional nanofibers and nanotubes as well as three-dimensional monoliths. However, the synthesis of porous polymers with two-dimensional (2D) sheet structures remains little explored. Colson et al. employed a solvothermal method to grow oriented two-dimensional COF thin films on substrate- supported graphene by the dynamic assembly of boronic acid and hexahydroxytriphenylene monomers, but the large-scale production of free-standing two-dimensional porous polymer networks has not yet been achieved.

Porous polymers, such as conjugated microporous polymers [Jiang et al. Conjugated mi- croporous poly (arylene ethynylene) networks. Angew. Chem. Int. Edit. 2007, 46 (45), 8574- 8578.], porous polymers based on Schiff base [Schwab et. Al. Catalyst-free Preparation of Melamine-Based Microporous Polymer Networks through Schiff Base Chemistry. J. Am. Chem. Soc. 2009, 131 (21 ), 7216-7217], and many other kinds of porous polymers, were developed in recent ten years. However, very rare work was reported on morphology control.

Colson et al. have successfully developed one solvothermal condensation method for production of two-dimensional COFs based on substrate supported graphene template [Colson Oriented 2D Covalent Organic Framework Thin Films on Single-Layer Graphene. Science 201 1 , 332 (6026), 228-231]. In this solvothermal condensation method, the substrate supported single layer graphene was immersed into the mesitylene:dioxane (1 :1 v/v) solution containing 1 ,4- phenylenebis(boronic acid) (PBBA) and 2,3,6,7,10,1 1 -hexahydroxytriphenylene (HHTP) , and then the mixture was kept under solvothermal condition. The COF-5 (a covalent organic framework based on 1 ,4-phenylenebis(boronic acid) and 2,3,6,7,10,1 1 - hexahydroxytriphenylene) can be produced as an insoluble powder at the bottom and also as a continuous film on the graphene surface. However, this reported method is limited by the graphene area and the volume of the reaction bottle and cannot be easily scaled-up. Most of the monomers are condensed as COF-5 and precipitated from solution, instead of loading on graphene surface. The interaction between graphene and COF-5 is very weak. In addition, the stability of the synthesized COF based material is very weak. The COF-5 is only loaded on one side of graphene. In previous work, [Yang et. Al. Graphene-Based Nanosheets with a Sandwich Structure.

Angew. Chemie Int. Edition 2010, 49 (28), 4795-4799], two-dimensional porous carbon was prepared by using graphene-based mesoporous silica sheet as template and sucrose as carbon source under high temperature pyrolysis followed by the removal of silica template. The aforementioned method offers a novel method for the preparation of two-dimensional porous carbons for the first time, however, the usage of inorganic mesoporous silica template is very critical.

The pore information, which is difficult for the fine tuning, such as pore diameter, pore depth and pore volume, comes from the pores of porous silica on graphene surfaces. In this method, malodorous silica sheets are used as hard template for filling carbon sources into their pores, followed by high temperature pyrolysis and then the silica template is etched using high toxic and hazardous HF solution. The obtained sample is then vacuum dried to yield the final two- dimensional porous carbons. This multi-step method of synthesis demands higher capital costs in terms of manpower, time and money. Besides, the carbon sources are very limited.

Therefore, all the above mentioned routes have several challenging aspects to obtain po- rous polymers and /or porous carbons. Hence there is a need to identify new "green" routes of producing stable porous polymers and / or porous carbons in large scale and cost effective ways.

SUMMARY OF THE INVENTION

To remove the deficiencies in the prior art, the present invention provides a new porous polymer and a porous carbon, and processes for producing the same.

In particular, the present invention provides a two-dimensional sandwich-type, graphene- based microporous polymer and a porous carbon obtained therefrom, and provides processes for producing the same.

In this invention, a graphene layer is sandwiched between the porous polymer, preferably by covalent bond. In this proposed reaction system, most of the monomers are polymerized onto the graphene surfaces. The produced two-dimensional graphene-based porous polymer is very stable and can be easily synthesized in large-scale. In this invention, the two-dimensional graphene-based porous polymer can be easily produced in one pot. The relative two-dimensional graphene-based porous carbon can be further prepared by only one-step high temperature pyrolysis. Furthermore, the nature of the two- dimensional graphene-based porous polymer can be tuned with regard to pore diameter and heteroatom type by modulating the length of the monomeric units and using monomers with different heteroatoms respectively.

DESCRIPTION OF THE DRAWINGS

Figure 1 shows the scheme of preparation of the graphene-based two-dimensional conjugated microporous polymer (GM P) and graphene-based two-dimensional mesoporous carbon (GMC) produced therefrom (Scheme 1 ).

Figure 2 shows the micropore size distribution of sulfur-containing conjugated microporous polymer (MP-S, not graphene-based) and sulfur-containing graphene-based two-dimensional conjugated microporous polymer (GM P-S).

Figure 3 shows the scheme of synthesis of Schiff base type two-dimensional graphene- based porous polymer (Scheme 2).

Figure 4 shows SEM, TEM and AFM images of graphene-based two-dimensional conju- gated microporous polymer.

Figure 5 shows CV curves of sulfur-containing mesoporous carbon (MC-S, not graphene- based) and sulfur-containing graphene-based two-dimensional mesoporous carbon (GMC-S) at 10 mV s ¹ in 6M KOH solution (left) and galvanostatic charge/discharge curves of MC-S and GMC-S at a current density of 0.1 Ag ¹ (right).

Figure 6 shows the electrochemical performance data of the two-dimensional mesoporous carbon (PC-1 , not graphene-based) and two-dimensional graphene-based porous carbon-1 (TPC-1 ) polymers (a) cyclic voltammogram in 6 M KOH at 10 mV s-1 (b) Charge / discharge curves (c) electrochemical impedance spectra and (d) schematic of the cell setup used for electrochemical testing, as explained in example 6.

Figure 7 shows the fluorescence decay of sulfur-containing conjugated microporous polymer (MP-S, not graphene-based) and sulfur-containing graphene-based two-dimensional con- jugated microporous polymer (GMP-S) monitored at 550-600 nm and the respective stretched exponential fits (A_ex = 400 nm). DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by anyone of ordinary skill in the art to which this invention belongs.

Expressions "a", "an", "the", when used to define a term, include both the plural and singular forms of the term.

The term "two-dimensional", in the present invention, means that the morphology of the graphene-based porous polymer of the invention is a sheet with aspect ratio (length or width to thickness) of more than 2.

In the present invention, the term "graphene-based two-dimensional porous polymer", the term "two-dimensional, graphene-based porous polymer" and the term "two-dimensional gra- phene-based porous polymer" and the like are used inter-changeably, which means that the porous polymer is two-dimensional, and is graphene-based. The same is for "graphene-based two-dimensional porous carbon" and the term "two-dimensional graphene-based porous carbon". In the present invention, the term "micro- pore" means a pore having width of less than

2nm, the term "meso- pore" means a pore having width of between 2-50nm, and the term "macro-pore" means a pore having width of more than 50 nm.

In the first aspect of the invention, the present invention relates to a graphene-based two- dimensional porous polymer, wherein a graphene layer is sandwiched between the porous polymer, preferably the graphene-based two-dimensional porous polymer are microporous, and preferably the graphene layer is sandwiched between the porous polymer by covalent bond.

Without intending to be bond to any theory, it is believed that the porous polymer of the in- vention is in form of networks, with a graphene layer being sandwiched between the porous polymer. The pore of the porous polymer is formed from the interaction of the monomeric units of the polymer. By changing the monomers with different length and/or different heteroatoms during polymerization, the pore size of the two-dimensional graphene-based porous polymer of the invention and heteroatom in the two-dimensional graphene-based porous polymer of the invention can be easily adjusted.

The polymerization for the two-dimensional, graphene-based porous polymer of the invention is not critical, provided that the polymerization can be used to prepare a porous polymer of the invention. For example, the two-dimensional, graphene-based porous polymer of the inven- tion may be prepared by a solution polymerization. In a preferred embodiment of the invention, the two-dimensional, graphene-based porous polymer of the invention is obtained from condensation, such as aldehyde-amino condensation. In another preferred embodiment of the inven- tion, the two-dimensional, graphene-based porous polymer of the invention is obtained by coupling reaction method, such as Sonogashira coupling reaction method.

Furthermore, the polymerization for the two-dimensional, graphene-based porous polymer of the invention may be carried out at any temperature and pressure that suitable for forming a porous polymer. In some embodiments of the invention, the polymerization of the invention is carried out at a temperature of between 0 to 200°C, preferably 0 to 150°C, or 10 to 100°C and a pressure of between 1 -10 atm, preferably 1 -5 atm, such as 2-3atm. The monomer suitable for forming the two-dimensional, graphene-based porous polymer of the invention may be any monomer that can be polymerized into a porous polymer, as can be selected by a skilled person. For example, actually all halogen-containing type monomers, aldhyde type monomers and alkyne type monomers are suitable for this invention. Preferably, dihalogen-containing type monomers, more preferably dibromo type monomers, such as 2,5- dibromothiophene, 2,5-dibromo-1 ,3-thiazole, 2,6-dibromopyridine, 3,8-dibromophenanthroline, 5,5'-dibromo-2,2'-bipyridine, 3,6-dibromopyridazine, 6,6'-Dibromoindigo, 2,4-dibromothiazole, 4,7-dibromo-2,1 ,3-benzothiadiazole; dialdhyde type monomers, such as 1 ,3-phthalaldehyde, 1 ,4-phthalaldehyde, 2,5-thiophenedialdehyde, 4,4'- biphenyldialdehyde and 2,6- pyridinedialdehyde; and trialkyne type monomers, such as 1 ,3,5-triethynylbenzene, tris(4- ethynylpheny)amine, are suitable monomers for the invention. Beside, trihalogen-containing type monomers and tetrahalogen-containing type monomers, preferably tribromo type monomers and tetrabromo type monomers, such as 2,4,6-tribromopyridine and 5,10,15,20-Tetrakis- (4-bromophenyl)-porphyrin-M, wherein M=Zn, Cu, Co, Fe, Ni, Pt, Pd, etc, are suitable monomers for the invention. In addition, amino-containing type monomers, for example triamino type monomers, such as melamine, are also suitable in the present invention. In some preferred embodiments of the invention, melamine is used for forming the two-dimensional, graphene- based porous polymer of the invention. In some preferred embodiments, dialdehyde/triamino or dibromo/triethynyl type monomers are used in the present invention. In a preferred embodiment of the invention, the two-dimensional, graphene-based porous polymer of the invention is a two-dimensional, graphene-based conjugated porous polymer or a Schiff-base type two-dimensional, graphene-based porous polymer.

The monomers listed above can be employed for forming the two-dimensional, graphene- based conjugated porous polymer of the invention, such as halogen-containing type monomers and alkyne type monomers. In some preferred embodiments of the invention, the monomer for forming the two-dimensional, graphene-based conjugated porous polymer of the invention are selected from the group consisting of dihalogen-containing type monomers, preferably dibromo type monomers, such as 2,5-dibromothiophene, 2,5-dibromo-1 ,3-thiazole, 2,6-dibromopyridine, 3,8-dibromophenanthroline, 5,5'-dibromo-2,2'-bipyridine, 3,6-dibromopyridazine, 6,6'- dibromoindigo, 2,4-dibromothiazole, 4,7-dibromo-2,1 ,3-benzothiadiazole; dialdehyde type monomers, such as 1 ,3-phthalaldehyde, 1 ,4-phthalaldehyde, 2,5-thiophenedialdehyde, 4,4'- bi- phenyldialdehyde and 2,6-pyridinedialdehyde; and trialkyne type monomers, such as 1 ,3,5- triethynylbenzene, tris(4-ethynylpheny)amine; and trihalogen-containing type monomers and tetrahalogen-containing type monomers, perferbaly tribromo type monomers, and tetrabromo type monomers, such as 2,4,6-tribromopyridine and 5,10,15,20-tetrakis-(4-bromophenyl)- porphyrin-M, wherein M=Zn, Cu, Co, Fe, Ni, Pt, Pd, etc.

Preferably, the graphene-based two-dimensional porous polymer of the invention may be obtained from polymerization of two or more monomers of different types. In some embodiments, a mixture of two different types monomers are used for obtaining the graphene-based two-dimensional porous polymer of the invention, such as for obtaining the two-dimensional, graphene-based conjugated porous polymer or the Schiff-base type two-dimensional, graphene-based porous polymer of the invention. In some preferred embodiments, the monomers are mixed in form of A_mB_n, wherein A and B respectively represents a monomer type as listed above, and m is the number of the monomer arms in the monomer A, and n is the number of the monomer arms in the monomer B, wherein the term "monomer arm" means the functional group of the monomer which participate in the polymerization, and wherein m > n>2 or n > m>2 or n=m > 2.

For example, for preparation of the Schiff-base type two-dimensional, graphene-based po- rous polymer of the invention, two kinds of monomers including an aldehyde type monomer and an amino-containing type monomer are involved according to the mode of A_mB_n, such as a dial- dehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a tri- amino type monomer, or a trialdehyde type monomer and a diamino type monomer, or mela- mine and a dialdehyde type monomer, or the like.

In some embodiments for preparation of the two-dimensional, graphene-based conjugated porous polymer of the invention, only halogen type monomers and alkyne type monomers are used according to the mode of A_mB_n, such as a dibromo type monomer and a trialkyne monomer, or a tribromo type monomer and a dialkyne monomer, or tetrabromo type monomers and a dialkyne monomers, or the like.

In some preferred embodiments of the invention, the monomers for forming the two- dimensional, graphene-based conjugated porous polymer of the invention contain both a halogen-containing type monomer, such as dibromo type monomers, tribromo type monomers, or tetrabromo type monomers, and a dialkyne type monomers or trialkyne type monomers, mixed according to above mentioned mode.

In some preferred embodiments of the invention, the monomer for forming the Schiff-base type two-dimensional, graphene-based porous polymer of the invention can be selected from the group consisting of melamine and dialdehyde monomers, such as 1 ,3-phthalaldehyde, 1 ,4- phthalaldehyde, 2,5-thiophenedialdehyde, 4,4'- biphenyldialdehyde and 2,6-pyridinedialdehyde. Preferably the monomers for forming the Schiff-base type two-dimensional, graphene-based porous polymer of the invention include melamine and dialdehyde type monomers, such as 1 ,3- phthalaldehyde, 1 ,4-phthalaldehyde, 2,5-thiophenedialdehyde, 4,4'- biphenyldialdehyde and 2,6-pyridinedialdehyde, mixed according to above mentioned mode. The two-dimensional, graphene-based porous polymer of the invention can integrate het- eroatom, metal, and metal oxide into the carbon framework of the polymer for various applications, such as energy storage and electrochemical catalysis, by using monomers or reactants having such heteroatoms, metals, and metal oxides in the structure. By polymerization, such heteroatoms, metals, and metal oxides are transferred to the obtained polymer. In the present invention, in such circumstance, it is called that the two-dimensional, graphene-based porous polymer of the invention is doped with heteroatom, metal, or metal oxide.

The suitable molecular weight of the two-dimensional, graphene-based porous polymer of the invention can be selected by a skilled person in the art.

In the second aspect of the invention, the present invention relates to a porous carbon produced from the two-dimensional, graphene-based porous polymer of the invention, preferably wherein the porous carbon is doped with heteroatoms from the monomer of the two- dimensional, graphene-based porous polymer.

In a preferred embodiment, the porous carbon of the invention is obtained/obtainable by direct pyrolysis of the two-dimensional, graphene-based porous polymer of the invention.

In some embodiments of the invention, the graphene-based porous carbon of the invention is obtained/obtainable by direct pyrolysis of the Schiff base type two-dimensional, graphene- based porous polymer of the invention. When analyzed by transmission electron microscope (TEM), the alternate dark and light information in TEM image demonstrates that there are many pores in this material, however, not all pores and channels maintained after pyrolysis because of the violent decomposition. The porous nature of the carbon sheet may be further confirmed by nitrogen physisorption measurements.

In some other embodiments of the invention, the graphene-based porous carbon of the invention is obtained/obtainable by direct pyrolysis of the graphene-based conjugated mi- croporous polymer of the invention.

The conjugated microporous polymer of the invention may be a type of carbon-rich precursor that can incorporate a heteroatom, metal, or metal oxide into the carbon framework of the polymer for various applications, such as energy storage and electrochemical catalysis. Ther- mogravimetric analysis (TGA) reveal that both graphene-based two-dimensional conjugated microporous polymer of the invention and a conjugated microporous polymer (not graphene- based) can feasibly be transformed into carbon materials with a high carbon yield, such as 70- 90%. The third aspect of the invention relates to a process for producing the two-dimensional, graphene-based porous polymer of the invention, comprising steps of: A. oxidizing graphene to form graphene oxide;

B. dispersing the graphene oxide in a solvent to form a dispersion;

C. adding a monomer to the dispersion and polymerizing the monomer to form the two- dimensional, graphene-based porous polymer. The above mentioned monomers are suitable for the process of the invention.

Preferably, in an embodiment of the invention, the process for producing the two- dimensional, graphene-based porous polymer of the invention comprises steps of: A. oxidizing graphene to form graphene oxide;

A1 . functionalizing the graphene oxide with an amino-functionalizing agent to obtain func- tionalized graphene oxide;

B. dispersing the functionalized graphene oxide in a solvent to form a dispersion;

C. adding a monomer to the dispersion and polymerizing the monomer to form the two- dimensional, graphene-based porous polymers of the invention.

The graphene used in the invention can be obtained from any suitable source, such as graphite. In the present invention, the graphene can be oxidized by any suitable method in the art. Furthermore, the solvent suitable for the process of the invention can be organic solvents, such as dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (NMP), N-ethyl pyrrolidone (NEP), chloroform and toluene. Preferably the solvent suitable for the process of the invention is dimethyl formamide (DMF).

In some preferred embodiments of the invention, the used halogen-containing monomers and alkyne monomers are soluble in the solvent used in the process of the invention, preferably di-/tri-/tetra-halogen-containing monomers and di-/tri-/tetra-alkyne monomers are all soluble in the solvent used in the process of the invention.

In the process of the invention, the polymerization initiator for polymerizing is not critical. A skilled person may make appropriate choice according to practical use.

In the process of the invention, polymerization catalyst may be used in the process of the invention. A skilled person may make appropriate choice for the polymerization catalyst according to practical use. For example, in some embodiments of the process of the invention, cata- lyst such as Pd[0]- or Pd[ll]-based catalysts can be used during polymerization. Furthermore, in some embodiments of the process of the invention, co-catalyst is used during the polymeriza- tion. For example, during a process of the invention, Cul (or it may be expressed as Cu[l]) may be used as a co-catalyst for activation of alkyne groups.

In some embodiments of the invention, polymerization catalyst may not be needed. For example, in some embodiments of the process of invention, in producing Schiff base type two- dimensional, graphene-based porous polymer of the invention, catalyst is not used.

The process of the invention may be carried out at any appropriate temperature and pressure. In some embodiments of the invention, the added monomer added to the process of the invention are polymerized at a temperature of between 0 to 200°C, preferably 0 to 150°C, or 10 to 100°C and a pressure of between 1 -10 atm, preferably 1 -5 atm, such as 2-3atm.

In a preferred embodiment, after step A and before step B, the process of the invention further comprises a step of

A1 . functionalizing the graphene oxide with a functionalizing agent to form a functionalized graphene oxide.

Preferably, the functionalizing agent is selected from the group consisting of amino- functionalizing agent, and bromo-functionalizing agent and reducing agent; more preferably before the graphene oxide is functionalized by bromo-functionalizing agent, the graphene oxide is reduced by a reducing agent. For example, amino-functionalized graphene oxide may suitable for obtaining the Schiff base type two-dimensional, graphene-based porous polymer of the invention, and bromo functionalized reduced graphene oxide may suitable for obtaining the two- dimensional, graphene-based conjugated porous polymer of the invention. Suitable amino- functionalizing agent includes all highly soluble diamino molecules, such as 1 ,3- diaminopropane , ethylenediamine , 1 ,4-diaminobutane. Suitable bromo-functionalizing agent may be any bromo-functionalizing agent suitable for the purpose of the invention, such as 4- bromophenyldiazoniumtetrafluoroborate. Suitable reducing agent may be any reducing agent suitable for the purpose of the invention, such as hydrazine monohydrate , sodium borohydrate and VITAMIN B12.

In the process of the present invention, during the polymerization, the functionalized graphene is much more easily dispersed in organic solvents (such as DMF and DMSO) and react- ed with the monomers than non- functionalized graphene. Thus, the polymerization takes place more easily on the surface of functionalized graphene than on the surface of non-functionalized graphene, and the morphology of graphene with large aspect ratio is maintained. The two- dimensional structure of porous polymer can be derived from the functionalized graphene incorporated during polymerization in one pot.

Without intending to be bound to any theory, it is believed that functionalized graphene is used as a two-dimensional template for polymerization on graphene surface. In particular, it is believed that the graphene oxide and/or functionalized graphene oxide in the present invention are used as template, directing growth of porous polymer of the invention with two-dimensional morphology, such as the Schiff base type two-dimensional, graphene-based porous polymer and the two-dimensional, graphene-based conjugated porous polymer of the invention.

In the present invention, thiophene-, thiazole-, and pyridine-based heterocycle monomers can be used to polymerize with 1 ,3,5-triethynylbenzene monomer on the graphene surface via the metal-catalyzed Sonogashira-Hagihara coupling reaction, to obtain the two-dimensional, graphene-based porous polymer of the invention. For example, in some preferred embodi- ments of the invention, thiophene-, thiazole-, and pyridine-based halogen-containing monomers containing sulfur and/or nitrogen heterocycles are mixed with alkyne monomer (such as 1 ,3,5- triethynylbenzene) and bromo-functionalized reduced graphene oxide in dry DMF, and then sealed and reacted under Sonogashira-Hagihara reaction conditions, to obtain the two- dimensional, graphene-based porous polymers of the invention. Most palladium based cata- lysts are suitable for the Sonogashira coupling reaction, such as

tetrakis(triphenylphosphine)palladiurr), 1 ,1 '-Bis(diphenylphosphino)ferrocene palladium dichlo- ride, Palladium(ll) acetate etc.

In a preferred embodiment of the invention, the process for producing the two-dimensional, graphene-based conjugated porous polymer of the invention, comprises the steps of:

A. reducing graphene oxide or graphene to form a reduced graphene oxide or a reduced graphene;

A1 . functionalizing the reduced graphene oxide or the reduced graphene with a functional- izing agent to form a functionalized reduced graphene oxide or a functionalized reduced graphene, preferably the functionalizing agent is bromo-functionalizing agent.

B. dispersing the functionalized reduced graphene oxide or the functionalized reduced graphene in a solvent to form a dispersion;

C. adding a monomer to the dispersion and polymerizing the monomer into the two- dimensional, graphene-based conjugated porous polymer.

In another preferred embodiment of the invention, the process for producing the Schiff base type two-dimensional, graphene-based porous polymer of the invention, comprises the steps of: A. oxidating graphene to form graphene oxide;

A1 . functionalizing the graphene oxide with an amino-functionalizing agent to obtain functionalized graphene oxide;

C. adding a monomer to the dispersion and polymerizing the monomer into the Schiff base type two-dimensional, graphene-based porous polymer of the invention. In the present invention, the Brunauer-Emment-Teller (BET) specific surface area of the porous polymer of the invention was measured on ASAP 2010 M/C surface area and porosime- try analyzer (Micromeritics Instrument Corporation, USA) based on N2 adsorption. The two- dimensional porous polymer of the invention shows typical sheet morphology with 0.2-3 μιτι in length and width and 10-50 nm in thickness, and the BET surface areas of these polymer networks may be varied between 458 and 888 m² g-¹. The Schiff base type two-dimensional, gra- phene-based porous polymer shows typical sheet morphology with 0.2-2 μιτι in length and width and 10-250 nm in thickness, and the BET surface areas of these polymer networks are 330-900 m² g-¹. The pore widths of all the two-dimensional porous polymers are less than 2nm, which are typical microporous.

The fourth aspect of the invention relates to a use of two-dimensional, graphene-based porous polymer of the invention in light harvesting, sensing, gas separation and storage, catalysis, and energy storage and conversion.

The fourth aspect of the invention relates to a use of porous carbon of the invention in making electrochemical double layer capacitor or otherwise termed as supercapacitor.

The present invention has many advantages, for example,

1 . The functionalized graphene template used in the present invention can be prepared in large scale because the precursor graphene oxide can be prepared in kilogram scale. The suitable monomers are all commercially available and very cheap.

2. In this invention, two-dimensional morphology of the two-dimensional, graphene-based porous polymer and the two-dimensional, graphene-based porous carbon can be easily controlled by using the functionalized graphene and can be synthesized in large-scale. The two-dimensional, graphene-based porous carbon is the direct pyrolysis product of two- dimensional graphene-based porous polymer without using any inorganic porous template. The electrochemical double layer capacitance of the two-dimensional graphene-based po- rous carbon of the invention is improved as compared with those of porous carbons derived from the porous polymers without using graphene template.

3. The produced two-dimensional graphene-based porous polymer is covalently attached onto the surface of graphene, thus is very stable and can be easily synthesized in large- scale.

4. the present invention offers an in situ process for preparing the two-dimensional graphene-based porous polymer.

5. The two-dimensional graphene-based porous carbon of the invention is produced from the two-dimensional graphene-based porous polymer of the invention via direct high temperature pyrolysis without using any inorganic porous templates, and of course without any further treatment for removing the inorganic porous template, thus the processes of the invention are simple and environmental friendly.

6. The pore width of the pores distributed on graphene surface is more narrowly distributed than that of normal porous carbons derived from porous polymers.

7. The electrochemical double layer capacitance of the two-dimensional graphene-based porous carbon is improved as compared with those of porous carbons derived from the porous polymers without using graphene template.

In particular, the present invention relates to following embodiments.

1 . A two-dimensional, graphene-based porous polymer, wherein a graphene layer is sandwiched between the porous polymer, preferably the porous polymer is microporous, prefer- ably the graphene layer is sandwiched between the porous polymer by covalent bond.

2. The two-dimensional, graphene-based porous polymer of embodiment 1 , wherein the porous polymer is in form of network, with the graphene being sandwiched between the porous polymer by covalent bond.

3. The two-dimensional, graphene-based porous polymer of embodiment 1 or 2, wherein the porous polymer is produced from the polymerization of a monomer selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino- containing type monomers, and aldehyde type monomers.

4. The two-dimensional, graphene-based porous polymer of any one of embodiments 1 -3, wherein the porous polymer is produced from the polymerization of a mixture of two differ- ent types monomers mixed in form of A_mB_n, wherein A and B respectively represents a monomer type selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino-containing type monomers, and aldehyde type monomers, and m is the number of the functional groups participating in the polymerization in the monomer A, and n is the number of the functional groups participating in the polymerization in the monomer B, and wherein m > n>2 or n > m>2 or n=m > 2.

5. The two-dimensional, graphene-based porous polymer of any one of embodiments 1 -4, wherein the porous polymer is a two-dimensional, graphene-based conjugated porous polymer or a Schiff-base type two-dimensional, graphene-based porous polymer.

6. The two-dimensional, graphene-based porous polymer of embodiment 5, wherein the two-dimensional, graphene-based conjugated porous polymer is produced from the polymerization of a mixture of a halogen type monomer and an alkyne type monomer mixed according to the mode of A_mB_n, such as a dibromo type monomer and a trialkyne monomer, or a tribromo type monomer and a dialkyne monomer, or tetrabromo type monomers and a dialkyne monomers, wherein A_mB_n has the same meaning as defined in em- bodiment 4.

7. The two-dimensional, graphene-based porous polymer of embodiment 5, wherein the Schiff-base type two-dimensional, graphene-based porous polymer is produced from the polymerization of a mixture of an aldehyde type monomer and an amino- containing type monomer mixed according to the mode of A_mB_n, such as a dialdehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a diamino type monomer, or melamine and a dialdehyde type monomer, wherein A_mB_n has the same meaning as defined in embodiment 4, prefera- bly the Schiff-base type two-dimensional, graphene-based porous polymer is produced from the polymerization of the mixture of melamine and dialdehyde type monomers, such as 1 ,3-phthalaldehyde, 1 ,4-phthalaldehyde, 2,5-thiophenedialdehyde, 4,4'- biphenyldialde- hyde and 2,6-pyridinedialdehyde.

8. Porous carbon produced from the two-dimensional, graphene-based porous polymer of any one of embodiments 1 to 7, preferably by direct pyrolysis of the two-dimensional, graphene-based porous polymers.

9. The porous carbon of embodiment 8, wherein the porous carbon is doped with a het- eroatom, preferably the heteroatom is selected from the group consisting of O, N, S, and halogen, such as CI or Br.

10. A process for producing the two-dimensional, graphene-based porous polymer of any one of embodiments 1 -7, comprising:

A. Oxidizing graphene to form graphene oxide;

B. dispersing the graphene oxide in a solvent to form a dispersion;

C. adding a monomer to the dispersion and polymerizing the monomer into the two- dimensional, graphene-based porous polymers, preferably the monomer is polymerized via condensation, such as an aldehyde-amino condensation, or via a coupling reaction, such as the Sonogashira coupling reaction.

1 1 . The process of embodiment 10, wherein after step A and before step B, the process further comprises a step of

A1 . functionalizing the graphene oxide with a functionalizing agent to form a functionalized graphene oxide, preferably the functionalizing agent is selected from the group consisting of amino-functionalizing agent, bromo-functionalizing agent and reducing agent; more preferably before the graphene oxide is functionalized by bromo-functionalizing agent, the gra- phene oxide is reduced by a reducing agent, preferably the amino-functionalization agent is selected from the group consisting of all highly soluble biamino molecules, such as 1 ,3- diaminopropane , ethylenediamine , 1 ,4-diaminobutane; preferably the bromo- functionalization agent is 4-bromophenyldiazoniumtetrafluoroborate; and preferably the reducing agent is selected from the group consisting of hydrazine monohy- drate , sodiumborohydrate and Vitamin B12.

12. The process of embodiment 10 or 1 1 , wherein the monomer is selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino-containing type monomers, and aldehyde type monomers, preferably the monomer is a mixture of two different types monomers mixed in form of ΑηΒ_η, wherein A and B respectively represents a monomer type selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino-containing type monomers, and aldehyde type monomers, m is the number of the functional groups participating in the polymerization in the monomer A, and n is the number of the functional groups participating in the polymerization in the monomer B, and wherein m > n>2 or n > m>2 or n=m > 2.

13. A process for producing the two-dimensional, graphene-based conjugated porous polymer of embodiment 5, comprises the steps of: A. reducing graphene oxide or graphene with a reducing agent to form a reduced graphene oxide or a reduced graphene, preferably the reducing agent is selected from the group consisting of hydrazine monohydrate , sodium borohydrate and VITAMIN B12;

A1 . functionalizing the reduced graphene oxide or the reduced graphene with a functional- izing agent to form a functionalized reduced graphene oxide or a functionalized reduced graphene, preferably the functionalizing agent is selected from the group consisting of ami- no-functionalizing agent, and bromo-functionalizing agent, more preferably the functionalizing agent is bromo-functionalizing agent;

B. dispersing the functionalized reduced graphene oxide or the functionalized reduced gra- phene in a solvent to form a dispersion;

C. adding a monomer to the dispersion and polymerizing the monomer into the two- dimensional, graphene-based conjugated porous polymer, preferably the monomer is polymerized via condensation, such as an aldehyde-amino condensation, or via a coupling reaction, such as the Sonogashira coupling reaction.

14. the process of embodiment 13, wherein the monomer is a mixture of a halogen type monomer and an alkyne type monomer mixed according to the mode of A_mB_n, such as a dibromo type monomer and a trialkyne monomer, or a tribromo type monomer and a dialkyne monomer, or tetrabromo type monomers and a dialkyne monomers, wherein A_mB_n has the same meaning as defined in embodiment 12.

15. a process for producing the Schiff base type two-dimensional, graphene-based porous polymer of embodiment 5, comprises the steps of:

A. Oxidizing graphene to form graphene oxide;

A1 . functionalizing the graphene oxide with an amino-functionalizing agent to obtain a functionalized graphene oxide;

C. adding a monomer to the dispersion and polymerizing the monomer into the Schiff base type two-dimensional, graphene-based porous polymers, preferably the monomer is polymerized via condensation, such as an aldehyde-amino condensation, or via a coupling reaction, such as the Sonogashira coupling reaction.

16. the process of embodiment 15, wherein the monomer is a mixture of an aldehyde type monomer and an amino- containing type monomer mixed according to the mode of A_mB_n, such as a dialdehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a diamino type monomer, or melamine and a dialdehyde type monomer, wherein A_mB_n has the same meaning as defined in embodiment 12, preferably the monomer is a mixture of melamine and dialdehyde type monomers, such as 1 ,3-phthalaldehyde, 1 ,4-phthalaldehyde, 2,5- thiophenedialdehyde, 4,4'- biphenyldialdehyde and 2,6-pyridine dialdehyde.

17. use of the two-dimensional, graphene-based porous polymer of any one of embodiments 1 to 7 in light harvesting, sensing, gas separation and storage, catalysis, and energy storage and conversion.

18. Use of porous carbon of embodiment 8 or 9 in making a capacitance, preferably electrochemical double layer capacitor or supercapacitor. EXAMPLES

The present invention will be further illustrated hereinafter with the reference of the specific examples which are exemplary and explanatory only and are not restrictive.

Each part and percentage when used, if not defined otherwise, is provided on weight basis.

Example 1. Preparation of the two-dimensional graphene-based conjugated porous polymer and two-dimensional graphene-based porous carbon of the invention, and preparation of the control sample thereof

Preparation A.

The two-dimensional network (the graphene-based two-dimensional conjugated microporous polymer, GMP) was synthesized by palladium-catalyzed Sonogashira-Hagihara cross-coupling reaction of Bromo-functionalized reduced graphene oxide (RGBr), aryl ethynylenes and aryhalides.

First, RGBr (65mg) was sonicated in dry DM F (100 ml.) until completely dispersed. Then, 1 ,3,5-triethynylbenzene (300 mg, 2.0 mmol), 2,5-dibromothiophene (484 mg, 2.0 mmol), tetrakis-(triphenylphosphine) palladium (35 mg, 0.03 mmol), copper iodide (7 mg, 0.03 mmol) and Et3N (4ml_) were dissolved in the RGBr dispersion. The reaction mixture was heated to 80 °C, stirred for 72 h under an argon atmosphere. Then, the insoluble precipitated network polymer was filtered and washed four times with chloroform, water, acetone and THF respectively to remove any unreacted monomer or catalyst residue. In addition, further purification of the pol- ymer was carried out by Soxhlet extraction with acetone for 48 h. The product was dried in vacuum for 24 h at 60 °C and grinded into a fine black powder, to obtain the sulfur-containing graphene-based two-dimensional conjugated microporous polymer (GMP-S).

The as-made two-dimensional porous polymer sulfur-containing graphene-based two- dimensional conjugated microporous polymer (GMP-S) was pyrolyzed at 800 °C for 2 h under an argon atmosphere to obtain a two-dimensional porous carbon i.e., sulfur-containing graphene-based two-dimensional mesoporous carbon (denoted as GMC-S).

The control sample sulfur-containing conjugated microporous polymer (MP-S, not gra- phene-based) was synthesized by the same procedure as described above, except that bromo- functionalized reduced graphene oxide (RGBr) is not used.

Control sample sulfur-containing mesoporous carbon (MC-S) was prepared from sulfur- containing conjugated microporous polymer (MP-S) by the same procedure as described above for producing GMC-S. Preparation B.

Graphene oxide (GO) was synthesized from natural graphite flake by a modified Hummers method according to W. S. J. Hummers, R. E. Offeman, J. Am. Chem. Soc. 1958, 80, 1339, and then reduced by hydrazine hydrate in the presence of sodium dodecylbenzenesulfonate under refluxing. The as-prepared surfactant-wrapped reduced graphene oxide (RGO) was cooled to room temperature. Functionalization was carried out by predissolving the solid diazonium salt (5 equivalents) in the minimum amount of water (the amount measured just at once the diazonium salt dissolved completely), and then the obtained solution was added dropwise with stirring to the reduced graphene oxide (RGO) dispersion. After 1 hour stirring at room temperature, the mixture was then poured into acetone. Purification of the as-prepared Bromo-functionalized reduced graphene oxide (RGBr) was performed by filtration and washing three times with water, acetone, and DM F respectively. The Purified as-prepared Bromo-functionalized reduced graphene oxide (RGBr) was vacuum dried before use. The GM P (the graphene-based two-dimensional conjugated microporous polymer) was built up by the palladium-catalyzed Sonogashira-Hagihara cross-coupling reaction of (RGBr), 1 ,3,5-triethynylbenzene, and aryl halides (2,5-dibromothiophene, 2,5-dibromo- 1 ,3-thiazole, and 2,6-dibromopyridine). A representative experimental procedure (for sulfur-containing graphene- based two-dimensional conjugated microporous polymer (GMP-S)) is given below.

First, RGBr (65 mg) was sonicated in dry DM F (100 ml.) until completely dispersed. Then, 1 ,3,5-triethynylbenzene (300 mg, 2.0 mmol), 2,5-dibromothiophene (484 mg, 2.0 mmol), tetrakis-(triphenylphosphine) palladium (35 mg, 0.03 mmol), copper iodide (7 mg, 0.03 mmol), and Et3N (4 ml.) were added to the (RGBr) dispersion. The reaction mixture was heated to 80 °C, and stirred for 72 h under an argon atmosphere. Then, the insoluble precipitated polymer network was filtered and washed four times with chloroform, water, acetone and THF respectively to remove any unreacted monomer or catalyst residue. Further purification of the polymer network was carried out by Soxhlet extraction with acetone for 48 h. The product was dried in vacuum for 24 h at 60 °C, and ground to a fine black powder. The control sample (sulfur- containing conjugated microporous polymers (MP-S, not graphene-based)) was synthesized by the same procedure without involving RGBr.

The as-prepared sulfur-containing graphene-based two-dimensional conjugated microporous polymer (GM P-S) was pyrolyzed at 800 °C for 2 h under an argon atmosphere, affording sulfur-containing graphene-based two-dimensional mesoporous carbon (denoted GMC- S). The control sample sulfur-containing mesoporous carbon (MC-S) was prepared from sulfur- containing conjugated microporous polymer (MP-S) by the same procedure.

Figure 1 shows the Preparation of the graphene-based two-dimensional conjugated microporous polymer (GMP) and the graphene-based two-dimensional mesoporous carbon (GMC) (Scheme 1 ). Example 2. Comparison of the two-dimensional graphene-based conjugated porous polymer and two-dimensional graphene-based porous carbon of the invention with the corresponding control samples The two-dimensional graphene-based conjugated porous polymer and two-dimensional graphene-based porous carbon of the invention are compared with the corresponding control samples prepared in example 2 according to the micropore size distribution.

The micropore size distribution of GM P-S and MP-S is presented in Figure 2. It is seen that the pore width of both M P-S and GM P-S are less than 2nm. GMP-S shows less pores which larger than 2nm than M P-S.

Example 3. Preparation of Schiff-Base-type two-dimensional graphene-based porous polymer and relative two-dimensional graphene-based porous carbon, and Preparation of the control sample thereof

Preparation A.

In a Schlenk flask fitted with a condenser and a magnetic stirring bar, an amino- functionalized graphene oxide (AGO, 1 equiv, weight) was dispersed in dry dimethyl sulfoxide to form a solution and then melamine and m-phthalaldehyde (4 equiv, molar ratio is 2:3) were added to the solution. After Ar bubbling for at least 2 hours, the Schlenk flask fitted with a condenser and a magnetic stirring bar was heated to 180°C for 72 h under an inert atmosphere. Before cooling to room temperature the precipitates were isolated by quick filtration and then washed with excess DMF and acetone, followed by Soxhlet extraction for 3 days using tetrahy- drofuran. The solvent was removed under vacuum at room temperature to afford the Schiff- base type two-dimensional graphene-based porous polymer-1 (TPP-1 ) (20%) as fluffy powder in good yields (79%).

TPP-1 was placed in a quartz boat and heated to 800°C under the heating rate of 5°Cmin ¹ under an argon flow. The sample was held at the temperature for 2 h. After cooling to room temperature, the black powder two-dimensional graphene-based porous carbon-1 (TPC-1 ) was recovered.

For control experiments, bare porous polymer (PP) without AGO template was prepared by the same procedure. The prepared bare porous polymer was placed in a quartz boat and heated to 800°C under the heating rate of 5°Cmin ¹ under an argon flow. The sample was held at the temperature for 2 h. After cooling to room temperature, the two-dimensional porous carbon (PC) was recovered as black powder. Preparation B.

1. Preparation of aminated graphene oxide (AGO): Graphene oxide was synthesized from flake graphite according to a modified Hummer's method. Typically, graphite powder (5.0 g) was added into a mixture of 98% H2SO4 (150 ml.) and NaNC (3.75 g). After stirring at room temperature for 30 min, KMn0₄ (20 g) was added portionly in an hour, with stirring for another 20 hours. Five days later, deionized water (500ml_) was added and followed by H2O2 (30 ml.) slowly. Deionized water was used to wash the acid, metal ions and unreacted graphite residuals for several times. The upper yellowish solution was collected and freeze-dried after certification under 6000 rpm for 10 min. As-dried graphene oxide (1.0g) was then added to dry DMF (250 ml.) and sonicated for 24 h, then N- Hydroxysuccinimide (NHS, 3.4 g) and A/-(3-(dimethylamino) propyl) -Λ/'-ethylcarbodiimide hydrochloride (EDOHCI, 5.7 g) were added to the solution at 0°C. After stirring for 2 h at 0°C, 1 ,3- diaminopropane (2 ml.) was added, and the solution was stirring for 10 h at room temperature. The aminated graphene oxide (AGO) was afforded as black powder after deionized water and ethanol washing and following vacuum drying at 40°C overnight.

2. Synthesis of Schiff-base type two-dimensional graphene-based porous polymer-1 (TPP-1) (5%), TPP-1 (10%) and TPP-1 (20%):

In a Schlenk flask fitted with a condenser and a magnetic stirring bar, an aminated graphene oxide (AGO) (1 equiv, weight) was well dispersed in dry dimethyl sulfoxide (DMSO) and then melamine and m-phthalaldehyde (19 equiv, 9 equiv and 4 equiv respectively, molar ratio is 2:3) were added to the solution. After nitrogen bubbling for at least 2 hours, the Schlenk flask fitted with a condenser and a magnetic stirring bar was heated to 180°C for 72 h under an inert atmosphere. Before cooling to room temperature the precipitates were isolated by quick filtration to remove the free particles not stand on graphene surfaces and then washed with excess DMF and acetone and followed by soxhlet fraction for 3 days using TH F. The solvent was re- moved under vacuum at room temperature to afford the materials as fluffy powders in good yields (70-90%).

3. Pyrolysis of TPP-1 (5%), TPP-1 (10%) and TPP-1 (20%): 200mg TPP-1 (5%) was placed in a quartz boat and heated to X°C (X=700, 800 and 900) under the heating rate of 5°C/min under an argon flow. The sample was held at the temperature for 2 h. After cooling to room temperature, the black powder TPC-1 (5%)-X°C was recovered. For samples two-dimensional graphene-based porous carbon-1 (TPC-1 ) (10%) and TPC- 1 (20%) with different graphene contents, pyrolized products TPC-1 (10%)-X°C, and TPC- 1 (20%)-X°C, were also obtained using the same procedure. The Synthesis of Schiff base type two-dimensional graphene-based porous polymer (Scheme 2) is shown in Figure 3.

Example 4. comparison of the morphology of the graphene-based two-dimensional porous pol- ymer and the graphene-based two-dimensional porous carbon with the two-dimensional porous polymers and the two-dimensional porous carbons that are not graphene-based

Figure 4 shows imagines of Graphene-based two-dimensional conjugated microporous polymer, wherein (a) is SEM images of sulfur-containing graphene-based two-dimensional con- jugated microporous polymer (GMP-S), (b) is AFM images of GMP-S, (c) is TEM images of GMP-S, and (d) is SEM image of sulfur-containing conjugated microporous polymer (MP-S).

All of the GM Ps showed similar sheet morphology. Thus, the results of GMP-S are discussed here as a typical example. As shown in Figure 4, many free-standing sheets with morphology similar to that of graphene and with sizes ranging from 200 nm to several micrometers were observed. In addition, these porous polymer sheets exhibited wrinkles and flexible features. No free porous polymer particles or naked graphene sheets appeared in either the TEM or SEM visualizations. This suggests that, as expected, most of the monomers have been polymerized on the surface of graphene. Typical AFM and thickness analyses (Figure b) of Figure 4) revealed the same morphology as observed with SEM and TEM, with a uniform thickness of 40 ± 3 nm. The control sample M P-S without the graphene template exhibited the common amorphous nanoparticle structure (Figure d) of Figure 4) as reported in the prior art. These results strongly suggest the crucial role of graphene as a substrate for the grafting of conjugated microporous polymers within a 2D manner. Example 5. Comparison on Electrochemical performance

Supercapacitor behaviors of sulfur-containing graphene-based two-dimensional mesopo- rous carbon (GMC-S) and sulfur-containing mesoporous carbon (MC-S) were typically examined and the results were shown in Figure 5. Figure 5 shows CV curves of MC-S and GMC-S at 10 mV s ¹ in 6M KOH solution (left) and Galvanostatic charge/discharge curves of MC-S and GMC-S at a current density of 0.1 Ag ¹ (right).

As shown in Figure 5 (left), symmetric and horizontal CV curves were observed for both MC-S and GMC-S, indicating ideal capacitive behavior. A prominent higher current density was observed for GMC-S than that of MC-S, which suggested that graphene layer contributes to the increase in the capacitance. The capacitive performance was further investigated with galvanostatic charge/discharge cycling experiments (Figure 5, right). On the basis of the discharging curve line, the specific capacitance of the GMC-S was calculated to be 268 Fg ¹ at 0.1 Ag ¹, which was 12% higher than that of the MC-S (235 Fg ¹). In this supercapacitor application, the graphene layer in sandwich-type GMCs can act as both mini-current collector and long-distance in-plane charge transporter during catalysis and charge/discharge processes because of the high conductivity and two-dimensional conjugated feature. Example 6. Comparison on Supercapacitor performances

The Comparison on Supercapacitor performances are shown in Figure 6.

Supercapacitor performances of two-dimensional graphene-based porous carbon (TPC) and the two-dimensional porous carbon (PC) which are prepared from bare porous polymer without graphene template by the same condition are compared. Figure a) of Figure 6 shows CV curves of PC and TPC at 5 mV s ¹ in 6M KOH aqueous solution.

Figure b) of Figure 6 shows Galvanostatic charge/discharge curves of PC and TPC at a current density of 0.1 Ag ¹.

Figure c) of Figure 6 shows Nyquist plots of PC and TPC at open circuit voltage. The inset shows the expanded high-frequency region of the plots.

Figure d) of Figure 6 shows the storage and release of electrons in TPC sheets, where graphene acts as mini-current collectors and in-plane conductor during charge and discharge processes. The pyrolized temperature 800°C was used to prepare these samples.

All two-dimensional graphene-based porous carbon (TPC) under electrical capacitance testing are pyrolized products of the corresponding Schiff-Base-Type two-dimensional gra- phene-based porous polymer under 800°C. As shown in the cyclic voltammetry (CV) curves in Figure a) of Figure 6, symmetric and horizontal CV curves were observed for both PC and TPC films, indicating ideal capacitive behavior. The capacitive performance was further investigated with galvanostatic charge/discharge cycling experiments (Figure b) of Figure 6). The specific capacitance of the TPC was calculated to be 424 Fg ¹ at 0.1 Ag ¹, which was almost 20% higher than that of the PC (354Fg ¹). Significant internal resistance (IR) drops reflecting the poor conductivity and large resistance of the electrode carbon material can be observed in PC. In contrast, almost no IR drop can be detected in TPC. The impedance spectra of PC and TPC, which were presented in Figure c) of Figure 6, also reveal this. A smaller semicircles of TPC indicates smaller charge transfer resistance. According to the equivalent circuit, the charge transfer resistances were calculated to be 0.17 Ω and 0.69 Ω for TPC and PC respectively. A lowering of the equivalent series resistance (ESR) is critical in increasing the specific power output of the supercapacitor. As illustrated in Figure d) of Figure 6, the graphene layer in this kind of sandwich type TPPs can act as both mini-current collector and long-distance in-plane charge transporter during charge and discharge processes because of the thermal reduced and two-dimensional conjugated features. Example 7. Comparison on effects of the conjugated nature of the polymer networks

Figure 7 shows the Fluorescence decay of sulfur-containing conjugated microporous polymer (MP-S) and sulfur-containing graphene-based two-dimensional conjugated microporous polymer (GMP-S) monitored at 550-600 nm and the respective stretched exponential fits (A_ex = 400 nm).

Given the conjugated nature of the polymer network, the exciton dynamics of GMP-S and MP-S by time-resolved photoluminescence spectroscopy properties were further investigated. As shown in Figure 7, MP-S exhibits a stretched exponential decay indicating a distribution of lifetimes. The decay can be fit with an inverse rate constant of 5.19 ps and a stretching exponent of 0.34. The stretching exponent (β = 0.31 ) is found to be similar to GMP-S, while the decay is significantly faster with an inverse rate constant of 1 .76 ps. This result implies that an electronic interaction exists between the graphene sheet and the porous polymer network in GMP-S, whose nature is subject of further investigation. However, it appears that the graphene sheet acts as an electron acceptor, while the conjugated microporous polymer shell serves as an electron donor. Such a sandwich-like D-A-D-type porous organic material using graphene sheets as an ultra-thin electron-accepting layer may hold promise for certain electronic applications.

Example 8. Comparison on effects of the heteroatoms doped in the graphene-based two- dimensional porous carbon sulfur-containing graphene-based two-dimensional mesoporous carbon (GMC-S), nitrogen and sulfur-containing graphene-based two-dimensional mesoporous carbon (GMC-NS), and nitrogen-containing graphene-based two-dimensional mesoporous carbon (GMC-N), denoted as GMC-S, GMC-NS and GMC-N, respectively, were generated by the direct pyrolysis of GM Ps at 800 °C for 2 h under an argon atmosphere. For comparison, mesoporous carbons were also prepared via the same procedure from sulfur-containing conjugated microporous polymer (MPs) but without involvement of the graphene template, and are denoted as MC-S, MC-NS, and MC- N, respectively. The weight contents of sulfur in GMC-S and GMC-NS were 7.7% and 5.9%, respectively, and the nitrogen ratio in GMC-NS and GMC-N reached 3.0% and 3.8%, respectively. This strategy thus realizes a feasible way to build up two-dimensional porous carbons with a high heteroatom doping content.

Example 9. Further performances Conjugated microporous polymer is a type of carbon-rich precursor that can integrate heteroatoms, metals, and metal oxides into the carbon framework for various applications, such as energy storage and electrochemical catalysis. Thermogravimetric analysis (TGA) revealed that both MPs and GMPs can feasibly be transformed into carbon materials with a high carbon yield (70-90%). Therefore, S-, N/S-, and N-doped two-dimensional porous carbons, denoted as GMC-S, GMC-NS and GMC-N, respectively, were generated by the direct pyrolysis of GMPs at 800 °C for 2 h under an argon atmosphere. It is of note that GMC-S, GMC-NS, and GMC-N maintain the two-dimensional morphology with a large aspect ratio as well as the porous feature with a high BET surface area of 618, 681 , and 560 m²g^_1 respectively. For comparison, porous carbons were also prepared via the same procedure from M Ps but without involvement of the graphene template, and are denoted as MC-S, MC-NS, and MC-N, respectively: their surface areas were in the range 554-636 m² g-¹. The decrease in the surface area for GMCs and MCs with respect to the corresponding GMPs and M Ps is probably due to the degradation of polymers and recombination of fragments under the carbonization conditions.)

Further Electrochemical performances are shown in table 1. Table 1 . Specific gravimetric capacitances (C_g) and specific capacitances per surface area

(CSA) of GMCs, MCs as well as literature reported graphene and N/S doped porous carbons.

GMC-NS: nitrogen and sulfur-containing graphene-based two-dimensional mesoporous carbon,

MC-NS: nitrogen and sulfur-containing mesoporous carbon

GMC-N: nitrogen-containing graphene-based two-dimensional mesoporous carbon,

MC-NS: nitrogen -containing mesoporous carbon

For Schiff base type porous polymers:

The alternate dark and light information in TEM image demonstrates that there are many pores in this material, however, not all pores and channels can be maintained after pyrolysis because of the violent decomposition. The porous nature of the carbon sheets is further confirmed by nitrogen physisorption measurements. The pore size distribution curve indicates the presence of mesopores and has a maximum peak at the pore diameter of -2.6 nm. The specifi surface areas still exhibit as high as 399, 364 and 323 m²g ¹ for pyrolysis at 700, 800 and 900°C, respectively. The nitrogen content reduced from 25.6 % before pyrolysis to 12.7%, 10.0% and 7.8% while carbonization under inert atmosphere at 700°C, 800°C and 900°C respectively. Each of the documents referred to above is incorporated herein by reference.

Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, and the like, are to be understood as modified by the word "about".

It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements.

The present invention is not to be limited in scope by the specific embodiments and examples described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and the accompanying figures. Such modifications are intended to fall within the scope of the appended claims.

Claims

1 . A two-dimensional, graphene-based porous polymer, wherein a graphene layer is sandwiched between the porous polymer, preferably the porous polymer is microporous, preferably the graphene layer is sandwiched between the porous polymer by covalent bond.

2. The two-dimensional, graphene-based porous polymer of claim 1 , wherein the porous polymer is in form of network, with the graphene being sandwiched between the porous polymer by covalent bond.

3. The two-dimensional, graphene-based porous polymer of claim 1 or 2, wherein the porous polymer is produced from the polymerization of a monomer selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino-containing type monomers, and aldehyde type monomers.

4. The two-dimensional, graphene-based porous polymer of any one of claims 1 -3, wherein the porous polymer is produced from the polymerization of a mixture of two different types monomers mixed in form of A_mB_n, wherein A and B respectively represents a monomer type selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino-containing type monomers, and aldehyde type monomers, and m is the number of the functional groups participating in the polymerization in the monomer A, and n is the number of the functional groups participating in the polymerization in the monomer B, and wherein m > n>2 or n > m>2 or n=m > 2.

5. The two-dimensional, graphene-based porous polymer of any one of claims 1 -4, wherein the porous polymer is a two-dimensional, graphene-based conjugated porous polymer or a Schiff-base type two-dimensional, graphene-based porous polymer.

6. The two-dimensional, graphene-based porous polymer of claim 5, wherein the two- dimensional, graphene-based conjugated porous polymer is produced from the polymerization of a mixture of a halogen type monomer and an alkyne type monomer mixed according to the mode of A_mB_n, such as a dibromo type monomer and a trialkyne monomer, or a tribromo type monomer and a dialkyne monomer, or tetrabromo type monomers and a dialkyne monomers, wherein A_mB_n has the same meaning as defined in claim 4.

7. The two-dimensional, graphene-based porous polymer of claim 5, wherein the Schiff- base type two-dimensional, graphene-based porous polymer is produced from the polymerization of a mixture of an aldehyde type monomer and an amino- containing type monomer mixed according to the mode of A_mB_n, such as a dialdehyde type monomer and a triamino type mon- omer, or a trialdehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a diamino type monomer, or melamine and a dialdehyde type monomer, wherein AmBn has the same meaning as defined in claim 4, preferably the Schiff-base type two- dimensional, graphene-based porous polymer is produced from the polymerization of the mixture of melamine and dialdehyde type monomers, such as 1 ,3-phthalaldehyde, 1 ,4- phthalaldehyde, 2,5-thiophenedialdehyde, 4,4'- biphenyldialdehyde and 2,6-pyridinedialdehyde.

8. Porous carbon produced from the two-dimensional, graphene-based porous polymer of any one of claims 1 to 7, preferably by direct pyrolysis of the two-dimensional, graphene-based porous polymers.

9. The porous carbon of claim 8, wherein the porous carbon is doped with a heteroatom, preferably the heteroatom is selected from the group consisting of O, N, S, and halogen, such as CI or Br.

10. A process for producing the two-dimensional, graphene-based porous polymer of any one of claims 1 -7, comprising:

A. Oxidizing graphene to form graphene oxide;

B. dispersing the graphene oxide in a solvent to form a dispersion;

1 1 . The process of claim 10, wherein after step A and before step B, the process further comprises a step of

A1 . functionalizing the graphene oxide with a functionalizing agent to form a functionalized graphene oxide, preferably the functionalizing agent is selected from the group consisting of amino-functionalizing agent, bromo-functionalizing agent and reducing agent; more preferably before the graphene oxide is functionalized by bromo-functionalizing agent, the graphene oxide is reduced by a reducing agent, preferably the amino-functionalization agent is selected from the group consisting of all highly soluble biamino molecules, such as 1 ,3- diaminopropane , ethylenediamine , 1 ,4-diaminobutane; preferably the bromo-functionalization agent is 4-bromophenyldiazoniumtetrafluoroborate; and preferably the reducing agent is selected from the group consisting of hydrazine monohydrate , sodiumborohydrate and Vitamin B12.

12. The process of claim 10 or 1 1 , wherein the monomer is selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino-containing type monomers, and aldehyde type monomers, preferably the monomer is a mixture of two different types monomers mixed in form of A_mB_n, wherein A and B respectively represents a monomer type selected from the group consisting of halogen-containing type monomers, alkyne type monomers, amino-containing type monomers, and aldehyde type monomers, m is the number of the functional groups participating in the polymerization in the monomer A, and n is the num- ber of the functional groups participating in the polymerization in the monomer B, and wherein m > n>2 or n > m>2 or n=m > 2.

13. A process for producing the two-dimensional, graphene-based conjugated porous pol- ymer of claim 5, comprises the steps of:

A. reducing graphene oxide or graphene with a reducing agent to form a reduced graphene oxide or a reduced graphene, preferably the reducing agent is selected from the group consisting of hydrazine monohydrate , sodium borohydrate and VITAMIN B12;

A1 . functionalizing the reduced graphene oxide or the reduced graphene with a functional- izing agent to form a functionalized reduced graphene oxide or a functionalized reduced graphene, preferably the functionalizing agent is selected from the group consisting of amino- functionalizing agent, and bromo-functionalizing agent, more preferably the functionalizing agent is bromo-functionalizing agent;

14. the process of claim 13, wherein the monomer is a mixture of a halogen type monomer and an alkyne type monomer mixed according to the mode of A_mB_n, such as a dibromo type monomer and a trialkyne monomer, or a tribromo type monomer and a dialkyne monomer, or tetrabromo type monomers and a dialkyne monomers, wherein A_mB_n has the same meaning as defined in claim 12.

15. a process for producing the Schiff base type two-dimensional, graphene-based porous polymer of claim 5, comprises the steps of:

A. Oxidizing graphene to form graphene oxide;

C. adding a monomer to the dispersion and polymerizing the monomer into the Schiff base type two-dimensional, graphene-based porous polymers, preferably the monomer is polymer- ized via condensation, such as an aldehyde-amino condensation, or via a coupling reaction, such as the Sonogashira coupling reaction.

16. the process of claim 15, wherein the monomer is a mixture of an aldehyde type monomer and an amino- containing type monomer mixed according to the mode of A_mB_n, such as a dialdehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a triamino type monomer, or a trialdehyde type monomer and a diamino type monomer, or mela- mine and a dialdehyde type monomer, wherein A_mB_n has the same meaning as defined in claim 12, preferably the monomer is a mixture of melamine and dialdehyde type monomers, such as 1 ,3-phthalaldehyde, 1 ,4-phthalaldehyde, 2,5-thiophenedialdehyde, 4,4'- biphenyldialdehyde and 2,6-pyridine dialdehyde.

17. use of the two-dimensional, graphene-based porous polymer of any one of claims 1 to 7 in light harvesting, sensing, gas separation and storage, catalysis, and energy storage and conversion.

18. Use of porous carbon of claim 8 or 9 in making a capacitance, preferably electrochemi- cal double layer capacitor or supercapacitor.