WO2011132036A1 - Composite grapheno-metal oxide platelet method of preparation and applications - Google Patents

Composite grapheno-metal oxide platelet method of preparation and applications Download PDF

Info

Publication number
WO2011132036A1
WO2011132036A1 PCT/IB2010/055598 IB2010055598W WO2011132036A1 WO 2011132036 A1 WO2011132036 A1 WO 2011132036A1 IB 2010055598 W IB2010055598 W IB 2010055598W WO 2011132036 A1 WO2011132036 A1 WO 2011132036A1
Authority
WO
WIPO (PCT)
Prior art keywords
graphene
composite catalyst
oxide
metal oxide
preparation
Prior art date
Application number
PCT/IB2010/055598
Other languages
French (fr)
Inventor
Adélio Miguel MAGALHÃES MENDES
David Alfredo Pacheco Tanaka
Original Assignee
Universidade Do Porto
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Universidade Do Porto filed Critical Universidade Do Porto
Priority to EP10805644A priority Critical patent/EP2560754A1/en
Publication of WO2011132036A1 publication Critical patent/WO2011132036A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02Impregnation, coating or precipitation
    • B01J37/03Precipitation; Co-precipitation
    • B01J37/031Precipitation
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L9/00Disinfection, sterilisation or deodorisation of air
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/06Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
    • B01J21/063Titanium; Oxides or hydroxides thereof
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/06Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
    • B01J21/066Zirconium or hafnium; Oxides or hydroxides thereof
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/18Carbon
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/30Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/30Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/39Photocatalytic properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/30Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/391Physical properties of the active metal ingredient
    • B01J35/393Metal or metal oxide crystallite size
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/50Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61Surface area
    • B01J35/61310-100 m2/g
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61Surface area
    • B01J35/615100-500 m2/g
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/16Reducing
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/02Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the alkali- or alkaline earth metals or beryllium
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/06Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of zinc, cadmium or mercury
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/10Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/14Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of germanium, tin or lead
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/20Vanadium, niobium or tantalum
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/24Chromium, molybdenum or tungsten
    • B01J23/30Tungsten
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56Platinum group metals
    • B01J23/58Platinum group metals with alkali- or alkaline earth metals
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56Platinum group metals
    • B01J23/62Platinum group metals with gallium, indium, thallium, germanium, tin or lead
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56Platinum group metals
    • B01J23/63Platinum group metals with rare earths or actinides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/56Platinum group metals
    • B01J23/64Platinum group metals with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74Iron group metals
    • B01J23/745Iron
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/78Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with alkali- or alkaline earth metals
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/83Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/72Treatment of water, waste water, or sewage by oxidation
    • C02F1/725Treatment of water, waste water, or sewage by oxidation by catalytic oxidation

Definitions

  • the invention relates to composite graphene-metal oxide materials, the method of preparation and their applications. Taking advantage of the semi-conductor properties of metal oxides, these materials have great potential to be used in organic synthesis, solar cells, solar hydrogen production and synthesis of methanol.
  • graphene-Ti02 has excellent photocatalyt ic activity and can be used to degrade inorganic and organic pollutants in water and air, synthesis of organic compounds, production of hydrogen using solar cells and synthesis of methanol
  • photo active semiconductor like Ti0 2 When photo active semiconductor like Ti0 2 is illuminated with photons with energy equal or larger than the band gap, electrons (e ⁇ ) are excited from the valence band into the conduction band leaving a positive hole (h + ) ; the electrons migrate to the surface of graphene preventing the direct recombination with the holes and providing an adsorption site for the species to be oxidized. The holes became then available for conducting oxidation reactions on the photocatalyst surface.
  • the photocatalytic activity can be enhanced by: a) Increasing the surface area; b) Decreasing the recombination rate of the photo generated electron-hole ; c) Extend the light absorption to longer wavelengths.
  • Patent EP0997191 [4] describes the preparation of TiC supported at least partially on the surface of nanoparticles of Ti02. This material was produced by CVD treatment of Ti02 with gaseous hydrocarbons and a reductant agent, the material thus produced was able to photo-oxidize formaldehyde using visible light.
  • Patent US7524793B2 describes the preparation of photocatalytic Ti02 having atoms of carbon. This photocatalyst was manufactured by mixing a fine grained titanium compound with a specific area of at least 50 m2/g with an organic compound and subsequent thermal treatment at temperatures up to 350 °C. Carbon is present only on the surface of Ti02 particles, which is different from the carbon doped Ti02 described in [6] where carbon was claimed to be inserted inside Ti02 crystals.
  • Carbon nanotubes have a large electron storage capacity; they can accept and store photo- excited electrons from Ti0 2 retarding the recombination of the electron-hole pair.
  • carbon nanotubes provide a surface area similar to activated carbon and may enhance the photocatalytic activity acting as photosensitizer .
  • Graphene have very recently attracted considerable attention as a viable and inexpensive alternative to carbon nanotubes in nanocomposite materials.
  • Graphene is essentially a flattened carbon nanotube cut along its axes made of a two-dimensional crystalline sheet of carbon atoms arranged in a honeycomb lattice. It has two faces with no bulk in between, therefore reagents can attach to both graphene faces.
  • the great interest of graphene is because of its ultrathin geometry (is the thinnest known material) and properties such as high charge carrier mobility, excellent thermal conductivity and high mechanical strength (the strongest ever measured) [9].
  • the present invention discloses a composite material containing nanoparticles of Ti02 chemically bonded to a graphene platelet surfaces. This composite particle is in the range of micrometers in diameter and possesses no danger for the human beings like TiO nanoparticles may do.
  • the invention relates the process of synthesis and use of a new composite catalyst of graphene-metal oxide. It is based on a metal oxide that is presented in amorphous, semicrystalline or crystalline and/or oxohydrate and/or hydrated form and graphene and/or reduced graphene oxide.
  • the composite material is prepared by mixing an aqueous solution of graphene oxide and a solution of a metal source material dissolved in water or a water miscible solvent. After hydrolysis, the metal oxide is attached to graphene oxide by physical and/or chemical interaction. The graphene oxide can be converted into graphene by chemical reduction and/or thermal treatment under hydrogen. A change of color takes place after the reducing process.
  • the composite material has improved photoactivity due to: a) the high surface area; the nanosize metal oxide particles are dispersed on both surface sides of graphene, b) reduced rate of electron hole recombination; the high mobility of electrons and high electron storage of graphene makes the exchange of electrons with the titania easier, and c) adsorption of chemical species to be photodegraded and intermediate products on the surface.
  • the present invention refers to the process of preparation and application of a composite of graphene-metal oxide.
  • the platelets of graphene have been proved to be effective supports for metal-oxide catalysts.
  • the composite catalyst of platelets of graphene and metal oxides could be used in organic synthesis, solar cells, solar generation of hydrogen, synthesis of methanol, taking advantage of the semi-conductor properties of metal oxides or just by their catalytic properties.
  • the present invention refers to a composite catalyst, the method of preparation and their applications.
  • the catalyst of the present invention is composed of nanoparticles of metal oxides attached to platelets of graphene or reduced graphene-oxide .
  • the platelets are composed of one layer or multiple layers.
  • the thickness of the platelets of graphene is less than 1000 nm preferably between 1 to 100 nm.
  • the size of the nanoparticles of metal-oxide should be between 1 to 100 nm, and the metal-oxide is amorphous, semicrystalline or crystalline and/or in the oxohydrate and/or hydrate form.
  • the metal-oxide nanoparticles is selected from the group of Ti02, ZnO, Zr02, Fe203, W03, SrTi03, BaTi03, Nb205, KTa03, Sn02, Ta205, A1203, Ce02, Y203 or a mixture of them.
  • the metal oxide is doped or decorated doped material is selected from the group consisting of Pt, Pd, Ni, Cu, Fe, Rh, Ru, N, C or a mixture of them; and the concentration relative to the metal-oxide is between 0.5 to 20 weight percent.
  • the composite material has a surface area between 40 to 500 m2/g, preferably between 60 to 250 m2/g.
  • the method of preparation of the composite material comprises : a) Preparation of a solution of graphene oxide in water ; b) Preparation of a solution of the metal-oxide precursor in a solvent miscible with water; c) Mixture of both solutions prepared previously in the desired proportion; d) Precipitation of the solution obtained in c) by addition of a basic solution preferentially ammonia; e) Reduction of the graphene oxide by adding a reductant agent, preferentially N2H4 and heating the suspension at a convenient temperature and enough time to obtain a constant change of color of graphene.
  • the heating conditions can change according to the time and temperature of the process; for example, we verified that the constant change of color at temperatures higher than 30 °C for more than 2h, preferentially at 90 °C for about 12 h. ; . f) Filtration and washing of the precipitate.
  • the material thus obtained can be calcinated in a non- oxidant environment which can be an inert gas, NH3, hydrocarbons, at higher than 400 °C preferentially 450 °C for 2 h.
  • a non- oxidant environment which can be an inert gas, NH3, hydrocarbons, at higher than 400 °C preferentially 450 °C for 2 h.
  • the reduction of the graphene oxide to graphene is total or partial; and the composition of graphene is from 0.01 wt . % to 2 wt . % and preferably between 0.1 to 1 wt . % .
  • the graphene metal-oxide catalyst according to the invention displays improved photocatalytic activity than nanoparticles of Ti02. As the nanoparticles of Ti02 are attached strongly to both phases of graphene platelets; minimizes the risk of the particles to reach vital organ of living objects.
  • the composite catalyst is a photocatalyst .
  • H 2 S0 4 50 ml of H 2 S0 4 is added to 2 g of graphite at room temperature; the solution is cooled at 0 °C using an ice bath and then 7 g of KMn0 4 is added gradually. The mixture is heated at 35 °C and stirred for 2 h. After that, 300 ml of water is added into the mixture at 0 °C (ice bath) . Then H 2 0 2 (30%) is added until no gas is produced. The solid is filtered, washed with 250 ml of HC1 (0.1 M) and water (500 ml) . The graphene oxide is dried under vacuum at room temperature for 24 h and then triturated using a mortar.
  • Example 1 Preparation of Ti02-graphene composite titanium tetrachloride (6 g) is added dropwise under strong stirring into a 4 % solution of HC1. The stirring is continued until the solution becomes clear. 7 g of the graphene oxide solution is added and the solution stirred for another 30 minutes. Then NH 3 (28-30%) is added dropwise until the pH becomes 7. In order to reduce the graphene oxide 3 g of N2H4 is added and leave to react overnight at 90 °C. The Ti02-graphene is filtered and washed with water until no chloride was detected (formation of AgCl) and dried at 90 °C overnight.
  • Fig 1 shows a SEM image of the composite material, it can be seen that 10-15 nm Ti02 particles are present on the graphene platelets.
  • Example 2 Preparation of Ti02-graphene composite Potassium titanium oxide oxalate (3 g) is dissolved in 100 ml of water and stirred until the solution becomes clear. 3 g of the graphene oxide solution is added and stirred for another 30 minutes. Then NH3 (2 M) is added dropwise until pH 7. The graphene oxide is reduced by addition of 3 g of N2H4, the reduction is carried out overnight at 90 °C. The Ti02-graphene is filtered, washed with water and dried at 90 °C overnight. Then the composite material is calcinated at 450 °C for 2 h under nitrogen with heating rate of 2°C/min.
  • Example 3 Preparation of Ti02-graphene composite beads. - 1.3 g of hexadecylamine is dissolved in 150 ml of ethanol and 1 ml of KC1 (0.1 M in water) . To this solution 2 g of a solution of graphene oxide is added. Then titanium isopropoxide (4.5 g) is added dropwise under strong stirring; the solution was kept static for 24h. The precipitate is filtered and transferred into a flask. Then 3 g of N2H4 and 20 ml of water are added, the flask was closed and heated at 90 °C overnight. The composite material is calcinated at 450 °C for 2h under nitrogen with heating rate of 2°C/min. SEM images of the beads are shown in Fig 2.
  • Fig 2. SEM images of the Ti02-graphene beads.
  • Fig 3. Photocatalytic degradation of NO by graphene-Ti02 and P 25 Ti02. a) selectivity of conversion, b)percentage of conversion.
  • Garriga i Cabo 0. Gonzalez-Diaz, J. A. Herrera-Melian, J. Perez-Pena, G. Colon, J. A. Navio; "Ti02 activation by using activated carbon as a support: Part II. Photoreactivity and FTIR study", Appl. Catal. B Environ. 44, 153-160, 2003.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Water Supply & Treatment (AREA)
  • Epidemiology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hydrology & Water Resources (AREA)
  • Catalysts (AREA)

Abstract

The present invention relates to the method of preparation and applications of composite catalyst of grapheno-metal oxide. Graphene platelets demonstrated to be very convenient support for metal-oxides catalysts. In particular, grapheno-metal oxide platelets can be used advantageously in organic synthesis, solar cells, solar hydrogen production and synthesis of methanol, taking advantage of metal-oxide semi-conductor properties or just of catalytic properties.

Description

DESCRIPTION
"COMPOSITE GRAPHENO-METAL OXIDE PLATELET METHOD OF
PREPARATION AND APPLICATIONS"
Field of the invention
The invention relates to composite graphene-metal oxide materials, the method of preparation and their applications. Taking advantage of the semi-conductor properties of metal oxides, these materials have great potential to be used in organic synthesis, solar cells, solar hydrogen production and synthesis of methanol. In particular graphene-Ti02 has excellent photocatalyt ic activity and can be used to degrade inorganic and organic pollutants in water and air, synthesis of organic compounds, production of hydrogen using solar cells and synthesis of methanol
State-of-the-art
When photo active semiconductor like Ti02 is illuminated with photons with energy equal or larger than the band gap, electrons (e~) are excited from the valence band into the conduction band leaving a positive hole (h+) ; the electrons migrate to the surface of graphene preventing the direct recombination with the holes and providing an adsorption site for the species to be oxidized. The holes became then available for conducting oxidation reactions on the photocatalyst surface. The photocatalytic activity can be enhanced by: a) Increasing the surface area; b) Decreasing the recombination rate of the photo generated electron-hole ; c) Extend the light absorption to longer wavelengths. In order to improve the photocatalytic activity, it has been proposed the addition of metals to the metal oxides. Thus, Pt was deposited on the surface of Ti02. After excitation, the electron migrates to the metal where it is trapped and the electron-hole recombination reduced [ 1 ] ; the concentration of metal should be very small, because large concentrations are detrimental for the photoactivity [1] .
Addition of activated carbon increases the photocalytic activity of Ti02 due to the adsorption on the substrate of the reactants or the intermediate species on the activated carbon [2,3] . Carbon can be also used to reduce the band gap of Ti02 allowing absorption of photons in the visible region increasing the adsorption efficiency [4-7]
Patent EP0997191 [4] describes the preparation of TiC supported at least partially on the surface of nanoparticles of Ti02. This material was produced by CVD treatment of Ti02 with gaseous hydrocarbons and a reductant agent, the material thus produced was able to photo-oxidize formaldehyde using visible light.
Khan et al . [5] prepared Ti02 modified with carbon by flame pyrolysis using metallic titanium as precursor. The pyrolysis was carried out in the presence of products of combustion (C02 and water vapor) of a flame of natural gas with controlled addition of oxygen. In this material, some atoms of oxygen of the crystalline network were replaced with carbon allowing the absorption of light at wavelengths below 535 nm. This photocatalyst was efficient for water splitting .
In another paper [6], carbon was introduced in the structure of Ti02 by hydrolysis of titanium tetrachloride with tetrabutylammonium followed by the calcinations of one hour at 400 °C. The resultant dark brown material was 5 times more photoactive in the decomposition of 4- chlorophenol than Ti02 doped with nitrogen. In this case, the used of tetrabutylammoniumn in the precipitation process, produced relatively homogenous doped Ti02 particles .
Patent US7524793B2 describes the preparation of photocatalytic Ti02 having atoms of carbon. This photocatalyst was manufactured by mixing a fine grained titanium compound with a specific area of at least 50 m2/g with an organic compound and subsequent thermal treatment at temperatures up to 350 °C. Carbon is present only on the surface of Ti02 particles, which is different from the carbon doped Ti02 described in [6] where carbon was claimed to be inserted inside Ti02 crystals.
On the other hand, it was recently observed that the photocatalytic activity of Ti02 can be improved by adding carbon nanotubes [8] . Carbon nanotubes have a large electron storage capacity; they can accept and store photo- excited electrons from Ti02 retarding the recombination of the electron-hole pair. In addition, carbon nanotubes provide a surface area similar to activated carbon and may enhance the photocatalytic activity acting as photosensitizer .
Graphene have very recently attracted considerable attention as a viable and inexpensive alternative to carbon nanotubes in nanocomposite materials. Graphene is essentially a flattened carbon nanotube cut along its axes made of a two-dimensional crystalline sheet of carbon atoms arranged in a honeycomb lattice. It has two faces with no bulk in between, therefore reagents can attach to both graphene faces. The great interest of graphene is because of its ultrathin geometry (is the thinnest known material) and properties such as high charge carrier mobility, excellent thermal conductivity and high mechanical strength (the strongest ever measured) [9].
It was described the use of self-organized hybrid nanostructures of graphene-Ti02 to increase the charge- discharge ratio of lithium batteries [10] . The increase in efficiency was attributed to the increase of the electric conductivity of the graphene-Ti02 electrodes. A determinant step in the preparation of the material was the development of an anionic surfactant mediated growth of self-assembled metal oxide-graphene hybrid nanostructures.
It is been discussed if single nanoparticles of Ti02 are harmful for the human beings as they can penetrate even into the brain blood circulation. The present invention discloses a composite material containing nanoparticles of Ti02 chemically bonded to a graphene platelet surfaces. This composite particle is in the range of micrometers in diameter and possesses no danger for the human beings like TiO nanoparticles may do.
Description
The invention relates the process of synthesis and use of a new composite catalyst of graphene-metal oxide. It is based on a metal oxide that is presented in amorphous, semicrystalline or crystalline and/or oxohydrate and/or hydrated form and graphene and/or reduced graphene oxide.
The composite material is prepared by mixing an aqueous solution of graphene oxide and a solution of a metal source material dissolved in water or a water miscible solvent. After hydrolysis, the metal oxide is attached to graphene oxide by physical and/or chemical interaction. The graphene oxide can be converted into graphene by chemical reduction and/or thermal treatment under hydrogen. A change of color takes place after the reducing process. The composite material has improved photoactivity due to: a) the high surface area; the nanosize metal oxide particles are dispersed on both surface sides of graphene, b) reduced rate of electron hole recombination; the high mobility of electrons and high electron storage of graphene makes the exchange of electrons with the titania easier, and c) adsorption of chemical species to be photodegraded and intermediate products on the surface.
Summary of the invention
The present invention refers to the process of preparation and application of a composite of graphene-metal oxide. The platelets of graphene have been proved to be effective supports for metal-oxide catalysts. In particular, the composite catalyst of platelets of graphene and metal oxides could be used in organic synthesis, solar cells, solar generation of hydrogen, synthesis of methanol, taking advantage of the semi-conductor properties of metal oxides or just by their catalytic properties.
The present invention refers to a composite catalyst, the method of preparation and their applications.
The catalyst of the present invention is composed of nanoparticles of metal oxides attached to platelets of graphene or reduced graphene-oxide . The platelets are composed of one layer or multiple layers.
In a preferred embodiment, the thickness of the platelets of graphene is less than 1000 nm preferably between 1 to 100 nm.
In a more preferential embodiment the size of the nanoparticles of metal-oxide should be between 1 to 100 nm, and the metal-oxide is amorphous, semicrystalline or crystalline and/or in the oxohydrate and/or hydrate form.
In a preferential embodiment, the metal-oxide nanoparticles is selected from the group of Ti02, ZnO, Zr02, Fe203, W03, SrTi03, BaTi03, Nb205, KTa03, Sn02, Ta205, A1203, Ce02, Y203 or a mixture of them.
In other preferential embodiment, the metal oxide is doped or decorated doped material is selected from the group consisting of Pt, Pd, Ni, Cu, Fe, Rh, Ru, N, C or a mixture of them; and the concentration relative to the metal-oxide is between 0.5 to 20 weight percent. The composite material has a surface area between 40 to 500 m2/g, preferably between 60 to 250 m2/g.
The method of preparation of the composite material comprises : a) Preparation of a solution of graphene oxide in water ; b) Preparation of a solution of the metal-oxide precursor in a solvent miscible with water; c) Mixture of both solutions prepared previously in the desired proportion; d) Precipitation of the solution obtained in c) by addition of a basic solution preferentially ammonia; e) Reduction of the graphene oxide by adding a reductant agent, preferentially N2H4 and heating the suspension at a convenient temperature and enough time to obtain a constant change of color of graphene. The heating conditions can change according to the time and temperature of the process; for example, we verified that the constant change of color at temperatures higher than 30 °C for more than 2h, preferentially at 90 °C for about 12 h. ; . f) Filtration and washing of the precipitate.
The material thus obtained can be calcinated in a non- oxidant environment which can be an inert gas, NH3, hydrocarbons, at higher than 400 °C preferentially 450 °C for 2 h.
In a preferential embodiment, the reduction of the graphene oxide to graphene is total or partial; and the composition of graphene is from 0.01 wt . % to 2 wt . % and preferably between 0.1 to 1 wt . % .
The graphene metal-oxide catalyst according to the invention, displays improved photocatalytic activity than nanoparticles of Ti02. As the nanoparticles of Ti02 are attached strongly to both phases of graphene platelets; minimizes the risk of the particles to reach vital organ of living objects.
In an even more preferential embodiment, the composite catalyst is a photocatalyst .
Examples
The present invention will now be described in greater detail with reference to the following examples. The examples are for illustrative purposes only and are not intended to limit the scope of the invention.
Example of preparation of graphene oxide
50 ml of H2S04 is added to 2 g of graphite at room temperature; the solution is cooled at 0 °C using an ice bath and then 7 g of KMn04 is added gradually. The mixture is heated at 35 °C and stirred for 2 h. After that, 300 ml of water is added into the mixture at 0 °C (ice bath) . Then H202 (30%) is added until no gas is produced. The solid is filtered, washed with 250 ml of HC1 (0.1 M) and water (500 ml) . The graphene oxide is dried under vacuum at room temperature for 24 h and then triturated using a mortar.
Example of the preparation of the solution of graphene oxide .
75 mg of graphene oxide and 100 ml of water is sonicated using an ultrasonic bath for 7 h. The insoluble graphene is separated by centrifugation at 12000 rpm for 10 minutes.
Examples of preparation of the composite material . Example 1. Preparation of Ti02-graphene composite titanium tetrachloride (6 g) is added dropwise under strong stirring into a 4 % solution of HC1. The stirring is continued until the solution becomes clear. 7 g of the graphene oxide solution is added and the solution stirred for another 30 minutes. Then NH3 (28-30%) is added dropwise until the pH becomes 7. In order to reduce the graphene oxide 3 g of N2H4 is added and leave to react overnight at 90 °C. The Ti02-graphene is filtered and washed with water until no chloride was detected (formation of AgCl) and dried at 90 °C overnight. Then the composite material was calcinated at 450 °C for 2h under nitrogen with heating rate of 2°C/min. Fig 1 shows a SEM image of the composite material, it can be seen that 10-15 nm Ti02 particles are present on the graphene platelets.
Example 2. Preparation of Ti02-graphene composite Potassium titanium oxide oxalate (3 g) is dissolved in 100 ml of water and stirred until the solution becomes clear. 3 g of the graphene oxide solution is added and stirred for another 30 minutes. Then NH3 (2 M) is added dropwise until pH 7. The graphene oxide is reduced by addition of 3 g of N2H4, the reduction is carried out overnight at 90 °C. The Ti02-graphene is filtered, washed with water and dried at 90 °C overnight. Then the composite material is calcinated at 450 °C for 2 h under nitrogen with heating rate of 2°C/min.
Example 3. Preparation of Ti02-graphene composite beads. - 1.3 g of hexadecylamine is dissolved in 150 ml of ethanol and 1 ml of KC1 (0.1 M in water) . To this solution 2 g of a solution of graphene oxide is added. Then titanium isopropoxide (4.5 g) is added dropwise under strong stirring; the solution was kept static for 24h. The precipitate is filtered and transferred into a flask. Then 3 g of N2H4 and 20 ml of water are added, the flask was closed and heated at 90 °C overnight. The composite material is calcinated at 450 °C for 2h under nitrogen with heating rate of 2°C/min. SEM images of the beads are shown in Fig 2.
Example 4. Preparation of Zr02-graphene composite. -
6.3 g of zirconylnitrate is dissolved in 100 ml of water and stirred until the solution becomes clear. 4.2 g of graphene oxide solution is added and the solution stirred for another 30 minutes. Then NH3 (2M) is added dropwise until the pH becomes 7. In order to reduce the graphene oxide 3 g of N2H4 is added and leave to reacted overnight at 90 °C. The Zr02-graphene is filtered and dried at 90 °C overnight. Then the composite material is calcinated at 450 °C for 2h under nitrogen with heating rate of 2°C/min.
Photocatalytic activity
The photocatalytic activity of the composite material was compared with the commercially available P-25 Ti02 by the photodegradat ion of NO. Figure 3a clearly shows that the percentage of conversion of the Ti02-graphene material is much higher than P25. The conversion obtained with the Ti02-graphene photocatalyst is almost constant more than 90 %. However, P25 conversion has a long unsteady state period of time and reaches a much smaller steady state conversion, 63 % for the same operating conditions. Similarly, the selectivity (percentage of NO converted to N02 ~ and N03 ~) in the composite material is much higher than in P25 (Fig 3 b) .
Description of the Figures
Fig 1 - SEM image of Ti02-graphene composite.
Fig 2.- SEM images of the Ti02-graphene beads. Fig 3.- Photocatalytic degradation of NO by graphene-Ti02 and P 25 Ti02. a) selectivity of conversion, b)percentage of conversion.
References
1. Amy L. Linsebigler, Guangquan Lu, and John T. Yates, Jr;
"Photocatalysis on Ti02 Surfaces: Principles, Mechanisms, and Selected Results", Chem. Rev. 95, 735- 758, 1995.
2. Juan Matosa, Jorge Laine, Jean-Marie Herrmann, "Synergy effect in the photocatalytic degradation of phenol on a suspended mixture of titania and activated carbon"; Appl. Catal. B: Environ. 18, 281-291, 1998.
3. J. Arana, J. M. Dona-Rodriguez, E. Tello Rendon, C.
Garriga i Cabo, 0. Gonzalez-Diaz, J. A. Herrera-Melian, J. Perez-Pena, G. Colon, J. A. Navio; "Ti02 activation by using activated carbon as a support: Part II. Photoreactivity and FTIR study", Appl. Catal. B Environ. 44, 153-160, 2003.
4. Sugiyama, Kazuo, "Photocatalyst having visible light activity and uses thereof" EP0997191, 2000.
5. S. U.M.Khan, M. Al-Shahry, W. B. Ingler Jr. Efficient photochemical water splitting by chemically modified n- Ti02, Science 297, 2243-2245, 2002
6. S. Sakthivel, H. Kisch, Dayloght photocatalysis by carbon-modified titanium dioxide, Angew. Chem. Int. Ed. 42, 4908-4911, 2003
7. J. Orth-Gerber, H. Kisch, S. Shanmugasundaram; Titanium dioxide photocatalyst containing carbon and method for its production; US 7524793 B2, 2009 8. K. Woan, C. Pyrgiotakis, W. Sigmund, "Photocatalytic Carbon-Nanotube-Ti02 composites" Adv. Mater. 21,1-7,
2009
9. A.K. Geim, "Graphene: Status and Prospects"; Science, 234, 2009, 1530.
10. D. Wang, D. Choi, J. Li, Z. Yang, R. Kou, D. Hu, C. Wang, L. Saraf, J. Zhang, I. A., J. Liu. Self-assembled Ti02-graphene hybrid nanostructures for enhanced Li-Ion Insertion; ACS Nano, 3 907-914, 2009

Claims

Claims
1 - A composite catalyst comprising nanoparticles of metal oxide attached to graphene or reduced graphene oxide platelets, where the metal oxide is doped or decorated and the decorating or doping material has a concentration relative to the metal-oxide is between 0.5 wt . % to 20 wt . % .
2 - Composite catalyst according to claim 1 wherein the graphene platelets are composed of single of multiple layers of graphene.
3 - Composite catalyst according to claims 1 - 2 wherein the thickness of the graphene platelets are less than 500 nm.
4 - Composite catalyst according to claim 3 wherein the thickness of the graphene platelets is between 0.4 and 50 nm.
5 - Composite catalyst according to claim 1 wherein the nanoparticles of metal oxide are between 1 to 100 nm.
6 - Composite catalyst according to claims 1 and 5 wherein the nanoparticles of metal oxide is selected from the group of Ti02, ZnO, Zr02, Fe203, W03, SrTi03, BaTi03, Nb205, KTa03 , Sn02, Ta205, A1203, Y203, Ce02 or a mixture of them.
7 - Composite catalyst according to claims 1, 5-6 wherein the metal oxide is amorphous, semicrystalline or crystalline . 8 - Composite catalyst according to claims 1, 5-7 wherein the metal oxide is in the oxohydrate and/or hydrate form.
9 - Composite catalyst according to claim 1 wherein the doping or decorating material is selected from the group consisting of Pt, Pd, Ni, Cu, Fe, Rh, Ru, N, C or a mixture of them.
10 - Composite catalyst according to claims 1-9 wherein the surface area is between 40 and 500 m2/g, preferably between 60 and 250 m2/g.
11 - A process for preparation of the composite material described in claims 1-10 comprising the following steps: a) Preparation of a solution of graphene oxide in water ; b) Preparation of a solution of the metal-oxide precursor in a solvent miscible with water; c) Mixture of both solutions prepared previously in the desired proportion; d) Precipitation of the solution obtained in c) by addition of a basic solution preferentially ammonia; e) Reduction of the graphene oxide by addition of a reductant agent, preferentially N2H4 and heating the suspension at a convenient temperature and enough time to obtain a constant change of color of graphene. The heating conditions can change according to the time and temperature of the process; for example, we verified that the constant change of color at temperatures higher than 30 °C for more than 2h, preferentially at 90 °C for about 12 h; f) Filtration and washing of the precipitate. 12 - Process according to claim 11 comprising an additional step of calcinations under non-oxidant atmosphere.
13 - Process according to claim 12 wherein the non-oxidant atmosphere is an inert gas, NH3, N2H4 or hydrocarbons at more than 400 °C, preferably at 450 °C for 2 h.
14 - Process according to claims 11-13 wherein the composition of graphene is between 0.01 wt . % to 2 wt . % and preferably between 0.1 wt . % to 1 wt . % .
15 - Composite catalyst described in claims 1-10 and obtained by the processes of preparation described in claims 11-14 wherein it has photocatalytic activity.
PCT/IB2010/055598 2010-04-22 2010-12-06 Composite grapheno-metal oxide platelet method of preparation and applications WO2011132036A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP10805644A EP2560754A1 (en) 2010-04-22 2010-12-06 Composite grapheno-metal oxide platelet method of preparation and applications

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PT105064A PT105064A (en) 2010-04-22 2010-04-22 COMPOUND CATALYST OF METHYL-OXIDE PLATELETS, METHOD OF PREPARATION AND THEIR APPLICATIONS
PT105064 2010-04-22

Publications (1)

Publication Number Publication Date
WO2011132036A1 true WO2011132036A1 (en) 2011-10-27

Family

ID=44260108

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2010/055598 WO2011132036A1 (en) 2010-04-22 2010-12-06 Composite grapheno-metal oxide platelet method of preparation and applications

Country Status (2)

Country Link
PT (1) PT105064A (en)
WO (1) WO2011132036A1 (en)

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120168383A1 (en) * 2010-12-29 2012-07-05 Korea Institute Of Science And Technology Graphene-iron oxide complex and fabrication method thereof
CN102600823A (en) * 2012-04-17 2012-07-25 聊城大学 Preparation method of graphene/titania composite material
CN103084164A (en) * 2013-02-04 2013-05-08 上海交通大学 Preparation method of tantalum pentoxide nanoparticle/graphene composite photocatalyst
CN103143342A (en) * 2013-03-08 2013-06-12 上海交通大学 Preparation method of rodlike tantalum pentoxide nanocrystalline/graphene compound photocatalyst
CN103203460A (en) * 2013-03-14 2013-07-17 东南大学 Method for preparing grapheme-Ag nano-particle composite material
CN103215548A (en) * 2013-04-24 2013-07-24 厦门烯成新材料科技有限公司 Preparation method of metal nanoparticles doped graphene
KR101290956B1 (en) 2011-12-19 2013-07-30 서울대학교산학협력단 Synthesis of TiO2 nanorod-decorated graphene sheets to visible light photocatalyst
CN103274463A (en) * 2013-05-15 2013-09-04 陕西煤业化工技术研究院有限责任公司 Graphene-metal oxide composite material and preparation method thereof
CN103599805A (en) * 2013-11-20 2014-02-26 东华大学 Preparation and application of nitrogen doped graphene fuel cell catalyst
CN103638959A (en) * 2013-12-16 2014-03-19 南通农业职业技术学院 Preparation method of rodlike N-doped niobium pentoxide photocatalyst
CN103657630A (en) * 2013-12-21 2014-03-26 海安县吉程机械有限公司 Preparation of compound photocatalyst of rodlike niobium pentoxide and reduced graphene oxide
CN103691420A (en) * 2013-12-21 2014-04-02 海安县吉程机械有限公司 Mesoporous niobium pentoxide/graphene compound photocatalyst prepared by one-step self-assembly method
US20140151608A1 (en) * 2012-12-03 2014-06-05 Boe Technology Group Co., Ltd. Conductive graphene-metal composite material, the production method of the same and use of the same
WO2014099842A1 (en) * 2012-12-20 2014-06-26 Sunpower Technologies Llc Photo-catalytic systems for the production of hydrogen
WO2014207754A1 (en) 2013-06-25 2014-12-31 Council Of Scientific & Industrial Research Reduced graphene oxide-silver phosphate (rgo-agp) and a process for the preparation thereof for the photodegradation of organic dyes
CN105195123A (en) * 2015-07-20 2015-12-30 黑龙江大学 Method for preparing graphene-titanium dioxide composite photocatalyst through ultrasonic exfoliation
CN106076312A (en) * 2016-06-02 2016-11-09 河南理工大学 A kind of Nb (OH)5nano wire/redox graphene composite photo-catalyst and preparation method and application
CN106560230A (en) * 2016-06-03 2017-04-12 天津城建大学 Application of composite catalyst based on iron-and-nitrogen-codoped titanium dioxide to photocatalysis of nitric oxide
CN106560244A (en) * 2016-06-03 2017-04-12 天津城建大学 Composite photocatalyst of iron-and-nitrogen-codoped titanium dioxide and mesoporous carbon and preparation method thereof
CN108906064A (en) * 2018-07-26 2018-11-30 安徽锦华氧化锌有限公司 A kind of preparation method for the modified nano zinc oxide that photocatalytic degradation is strong
CN109433177A (en) * 2018-09-27 2019-03-08 天津大学 A kind of 2D-TiO2(B)/preparation method of graphene high-efficiency catalysis material and the application of the material
CN110624546A (en) * 2019-10-22 2019-12-31 特烯(厦门)科技有限公司 Preparation method of copper/graphene catalyst
CN110801857A (en) * 2019-12-02 2020-02-18 山东建筑大学 Method for preparing titanium dioxide-nitrogen doped graphene composite photocatalytic material
US10668458B2 (en) * 2015-09-23 2020-06-02 University Of Ulsan Foundation For Industry Cooperation Photocatalyst having high visible-light activity
US10888845B1 (en) 2020-07-17 2021-01-12 King Abdulaziz University Graphene-tungsten oxide-metal boride/hydroxide photocatalysts, and methods for organic pollutant degradation and hydrogen production
CN112841219A (en) * 2020-12-31 2021-05-28 广东金发科技有限公司 Efficient antibacterial agent and preparation method and application thereof
US11161094B2 (en) 2019-05-01 2021-11-02 Imam Abdulrahman Bin Faisal University Titania-carbon dot-reduced graphene oxide composites, their make, and use
CN114250096A (en) * 2021-11-30 2022-03-29 盘锦北方沥青股份有限公司 Complex ester type nano refrigerator oil and preparation method thereof
CN114452437A (en) * 2021-08-04 2022-05-10 江西理工大学 Medical zinc-based composite stent and preparation method thereof
CN114522701A (en) * 2022-04-22 2022-05-24 浙江晟格生物科技有限公司 Compound sulfate radical catalyst for biological sugar preparation, preparation method and application

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES1158584Y (en) * 2016-04-05 2016-09-09 Ramirez Alberto Andrés Santana Ionic power station
CN110228838A (en) * 2019-06-19 2019-09-13 南开大学 A kind of RGO/MoS2/Ce0.75Zr0.25O2Cathode material and its preparation method and application
CN111604070B (en) * 2020-06-28 2023-05-23 廊坊师范学院 Composite membrane photocatalyst and preparation method and application thereof
CN112625774A (en) * 2020-12-02 2021-04-09 陕西科技大学 Graphene-loaded cerium oxide nanoparticle composite material and preparation method thereof

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0997191A1 (en) 1996-11-25 2000-05-03 Ecodevice Laboratory Co., Ltd Photocatalyst having visible light activity and uses thereof
US7524793B2 (en) 2004-04-07 2009-04-28 Kronos International Inc Titanium dioxide photocatalyst containing carbon and method for its production

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0997191A1 (en) 1996-11-25 2000-05-03 Ecodevice Laboratory Co., Ltd Photocatalyst having visible light activity and uses thereof
US7524793B2 (en) 2004-04-07 2009-04-28 Kronos International Inc Titanium dioxide photocatalyst containing carbon and method for its production

Non-Patent Citations (17)

* Cited by examiner, † Cited by third party
Title
A.K. GEIM: "Graphene: Status and Prospects", SCIENCE, vol. 234, 2009, pages 1530
AMY L. LINSEBIGLER; GUANGQUAN LU; JOHN T.; YATES, JR: "Photocatalysis on Ti02 Surfaces: Principles, Mechanisms, and Selected Results", CHEM. REV., vol. 95, 1995, pages 735 - 758
C. NETHRAVATHI ET AL: "Graphite Oxide-Intercalated Anionic Clay and Its Decomposition to Graphene-Inorganic Material Nanocomposites", LANGMUIR, vol. 24, no. 15, 1 August 2008 (2008-08-01), pages 8240 - 8244, XP055003372, ISSN: 0743-7463, DOI: 10.1021/la8000027 *
D. WANG; D. CHOI; J. LI; Z. YANG; R. KOU; D. HU; C. WANG; L. SARAF; J. ZHANG; I. A., J. LIU.: "Self-assembled Ti02-graphene hybrid nanostructures for enhanced Li-Ion Insertion", ACS NANO, vol. 3, 2009, pages 907 - 914, XP002723824, DOI: doi:10.1021/nn900150y
DONGHAI WANG ET AL: "Self-assembled TiO2-Graphene hybrid nanostrucures for enhenced Li-ion insertion", NANO, WORLD SCIENTIFIC PUBLISHING CO. PTE. LTD, SG, vol. 3, no. 4, 1 January 2009 (2009-01-01), pages 907 - 914, XP002631600, ISSN: 1793-2920, [retrieved on 20090326], DOI: DOI:10.1021/NN900150Y *
DONGHAI WANG ET AL: "Ternary Self-Assembly of Ordered Metal Oxide-Graphene Nanocomposites for Electrochemical Energy Storage", ACS NANO, AMERICAN CHEMICAL SOCIETY, UNITED STATES, vol. 4, no. 3, 23 March 2010 (2010-03-23), pages 1587 - 1595, XP002643941, ISSN: 1936-0851, [retrieved on 20100225], DOI: DOI:10.1021/NN901819N *
HAILIANG WANG ET AL: "Nanocrystal Growth on Graphene with Various Degrees of Oxidation", JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, vol. 132, no. 10, 17 March 2010 (2010-03-17), pages 3270 - 3271, XP055003373, ISSN: 0002-7863, DOI: 10.1021/ja100329d *
J. ARANA; J. M. DONA-RODRIGUEZ; E. TELLO RENDON; C. GARRIGA I CABO; O. GONZÁLEZ-DÍAZ; J. A. HERRERA-MELIÁN; J. PEREZ-PENA; G. C: "Ti02 activation by using activated carbon as a support: Part II. Photoreactivity and FTIR study", APPL. CATAL. B ENVIRON., vol. 44, 2003, pages 153 - 160, XP055207807, DOI: doi:10.1016/S0926-3373(03)00075-4
JIANFENG SHEN ET AL: "One Step Synthesis of Graphene Oxide-Magnetic Nanoparticle Composite", JOURNAL OF PHYSICAL CHEMISTRY C, vol. 114, no. 3, 28 January 2010 (2010-01-28), pages 1498 - 1503, XP055003371, ISSN: 1932-7447, DOI: 10.1021/jp909756r *
JUAN MATOSA; JORGE LAINE; JEAN-MARIE HERRMANN: "Synergy effect in the photocatalytic degradation of phenol on a suspended mixture of titania and activated carbon", APPL. CATAL. B: ENVIRON., vol. 18, 1998, pages 281 - 291
K. WOAN; C. PYRGIOTAKIS; W. SIGMUND: "Photocatalytic Carbon-Nanotube-Ti02 composites", ADV. MATER., vol. 21, 2009, pages 1 - 7
KIM H ET AL: "Highly reversible Co3O4/graphene hybrid anode for lithium rechargeable batteries", CARBON, ELSEVIER, OXFORD, GB, vol. 49, no. 1, 1 January 2011 (2011-01-01), pages 326 - 332, XP027450953, ISSN: 0008-6223, [retrieved on 20101012], DOI: DOI:10.1016/J.CARBON.2010.09.033 *
S. SAKTHIVEL; H. KISCH: "Dayloght photocatalysis by carbon-modified titanium dioxide", ANGEW. CHEM. INT. ED., vol. 42, 2003, pages 4908 - 4911, XP001197710, DOI: doi:10.1002/anie.200351577
S. U.M.KHAN; M. AL-SHAHRY; W. B. INGLER JR: "Efficient photochemical water splitting by chemically modified n-Ti02", SCIENCE, vol. 297, 2002, pages 2243 - 2245, XP009086577, DOI: doi:10.1126/science.1075035
SHEN X ET AL: "One-pot solvothermal syntheses and magnetic properties of graphene-based magnetic nanocomposites", JOURNAL OF ALLOYS AND COMPOUNDS, ELSEVIER SEQUOIA, LAUSANNE, CH, vol. 506, no. 1, 10 September 2010 (2010-09-10), pages 136 - 140, XP027242844, ISSN: 0925-8388, [retrieved on 20100703] *
TIMOTHY N. LAMBERT ET AL: "Synthesis and Characterization of Titania-Graphene Nanocomposites", JOURNAL OF PHYSICAL CHEMISTRY C, vol. 113, no. 46, 19 November 2009 (2009-11-19), pages 19812 - 19823, XP055003443, ISSN: 1932-7447, DOI: 10.1021/jp905456f *
XIAOYING YANG ET AL: "Superparamagnetic graphene oxide-Fe3O4 nanoparticles hybrid for controlled targeted drug carriers", JOURNAL OF MATERIALS CHEMISTRY, vol. 19, no. 18, 1 January 2009 (2009-01-01), pages 2710, XP055003440, ISSN: 0959-9428, DOI: 10.1039/b821416f *

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120168383A1 (en) * 2010-12-29 2012-07-05 Korea Institute Of Science And Technology Graphene-iron oxide complex and fabrication method thereof
KR101290956B1 (en) 2011-12-19 2013-07-30 서울대학교산학협력단 Synthesis of TiO2 nanorod-decorated graphene sheets to visible light photocatalyst
CN102600823A (en) * 2012-04-17 2012-07-25 聊城大学 Preparation method of graphene/titania composite material
US9959946B2 (en) 2012-12-03 2018-05-01 Boe Technology Group Co., Ltd. Conductive graphene-metal composite material, the production method of the same and use of the same
US20140151608A1 (en) * 2012-12-03 2014-06-05 Boe Technology Group Co., Ltd. Conductive graphene-metal composite material, the production method of the same and use of the same
WO2014099842A1 (en) * 2012-12-20 2014-06-26 Sunpower Technologies Llc Photo-catalytic systems for the production of hydrogen
CN103084164A (en) * 2013-02-04 2013-05-08 上海交通大学 Preparation method of tantalum pentoxide nanoparticle/graphene composite photocatalyst
CN103143342A (en) * 2013-03-08 2013-06-12 上海交通大学 Preparation method of rodlike tantalum pentoxide nanocrystalline/graphene compound photocatalyst
CN103203460A (en) * 2013-03-14 2013-07-17 东南大学 Method for preparing grapheme-Ag nano-particle composite material
CN103215548A (en) * 2013-04-24 2013-07-24 厦门烯成新材料科技有限公司 Preparation method of metal nanoparticles doped graphene
CN103215548B (en) * 2013-04-24 2015-12-02 厦门烯成新材料科技有限公司 A kind of preparation method of metal nanoparticle doped graphene
CN103274463A (en) * 2013-05-15 2013-09-04 陕西煤业化工技术研究院有限责任公司 Graphene-metal oxide composite material and preparation method thereof
WO2014207754A1 (en) 2013-06-25 2014-12-31 Council Of Scientific & Industrial Research Reduced graphene oxide-silver phosphate (rgo-agp) and a process for the preparation thereof for the photodegradation of organic dyes
CN103599805A (en) * 2013-11-20 2014-02-26 东华大学 Preparation and application of nitrogen doped graphene fuel cell catalyst
CN103638959B (en) * 2013-12-16 2015-11-25 南通农业职业技术学院 The preparation method of the bar-shaped niobium pentaoxide photochemical catalyst of N doping
CN103638959A (en) * 2013-12-16 2014-03-19 南通农业职业技术学院 Preparation method of rodlike N-doped niobium pentoxide photocatalyst
CN103691420A (en) * 2013-12-21 2014-04-02 海安县吉程机械有限公司 Mesoporous niobium pentoxide/graphene compound photocatalyst prepared by one-step self-assembly method
CN103657630A (en) * 2013-12-21 2014-03-26 海安县吉程机械有限公司 Preparation of compound photocatalyst of rodlike niobium pentoxide and reduced graphene oxide
CN105195123A (en) * 2015-07-20 2015-12-30 黑龙江大学 Method for preparing graphene-titanium dioxide composite photocatalyst through ultrasonic exfoliation
US10668458B2 (en) * 2015-09-23 2020-06-02 University Of Ulsan Foundation For Industry Cooperation Photocatalyst having high visible-light activity
US10695758B2 (en) 2015-09-23 2020-06-30 University Of Ulsan Foundation For Industry Corporation Photocatalyst having high visible-light activity
CN106076312A (en) * 2016-06-02 2016-11-09 河南理工大学 A kind of Nb (OH)5nano wire/redox graphene composite photo-catalyst and preparation method and application
CN106560244A (en) * 2016-06-03 2017-04-12 天津城建大学 Composite photocatalyst of iron-and-nitrogen-codoped titanium dioxide and mesoporous carbon and preparation method thereof
CN106560230A (en) * 2016-06-03 2017-04-12 天津城建大学 Application of composite catalyst based on iron-and-nitrogen-codoped titanium dioxide to photocatalysis of nitric oxide
CN108906064A (en) * 2018-07-26 2018-11-30 安徽锦华氧化锌有限公司 A kind of preparation method for the modified nano zinc oxide that photocatalytic degradation is strong
CN109433177A (en) * 2018-09-27 2019-03-08 天津大学 A kind of 2D-TiO2(B)/preparation method of graphene high-efficiency catalysis material and the application of the material
US11161094B2 (en) 2019-05-01 2021-11-02 Imam Abdulrahman Bin Faisal University Titania-carbon dot-reduced graphene oxide composites, their make, and use
CN110624546A (en) * 2019-10-22 2019-12-31 特烯(厦门)科技有限公司 Preparation method of copper/graphene catalyst
CN110801857A (en) * 2019-12-02 2020-02-18 山东建筑大学 Method for preparing titanium dioxide-nitrogen doped graphene composite photocatalytic material
US10888845B1 (en) 2020-07-17 2021-01-12 King Abdulaziz University Graphene-tungsten oxide-metal boride/hydroxide photocatalysts, and methods for organic pollutant degradation and hydrogen production
CN112841219A (en) * 2020-12-31 2021-05-28 广东金发科技有限公司 Efficient antibacterial agent and preparation method and application thereof
CN114452437A (en) * 2021-08-04 2022-05-10 江西理工大学 Medical zinc-based composite stent and preparation method thereof
CN114250096A (en) * 2021-11-30 2022-03-29 盘锦北方沥青股份有限公司 Complex ester type nano refrigerator oil and preparation method thereof
CN114522701A (en) * 2022-04-22 2022-05-24 浙江晟格生物科技有限公司 Compound sulfate radical catalyst for biological sugar preparation, preparation method and application

Also Published As

Publication number Publication date
PT105064A (en) 2011-10-24

Similar Documents

Publication Publication Date Title
WO2011132036A1 (en) Composite grapheno-metal oxide platelet method of preparation and applications
Kadi et al. Soft and hard templates assisted synthesis mesoporous CuO/g-C3N4 heterostructures for highly enhanced and accelerated Hg (II) photoreduction under visible light
Prasad et al. An overview of graphene oxide supported semiconductors based photocatalysts: Properties, synthesis and photocatalytic applications
Bafaqeer et al. Well-designed ZnV2O6/g-C3N4 2D/2D nanosheets heterojunction with faster charges separation via pCN as mediator towards enhanced photocatalytic reduction of CO2 to fuels
Adhikari et al. Electrospinning directly synthesized porous TiO2 nanofibers modified by graphitic carbon nitride sheets for enhanced photocatalytic degradation activity under solar light irradiation
Brindha et al. Visible active N, S co-doped TiO2/graphene photocatalysts for the degradation of hazardous dyes
Liu et al. A sandwich-like heterostructure of TiO2 nanosheets with MIL-100 (Fe): a platform for efficient visible-light-driven photocatalysis
Hu et al. Synthesis, structures and applications of single component core-shell structured TiO2: a review
Xie et al. Advances in graphene-based semiconductor photocatalysts for solar energy conversion: fundamentals and materials engineering
Kumar et al. Solar light sensitized p-Ag2O/n-TiO2 nanotubes heterojunction photocatalysts for enhanced hydrogen production in aqueous-glycerol solution
Rostami Photodecomposition and adsorption of hazardous organic pollutants by Ce-doped ZnO@ Ce-doped TiO2-N/S-dual doped RGO ternary nano-composites photocatalyst for water remediation
Christoforidis et al. Single-step synthesis of SnS2 nanosheet-decorated TiO2 anatase nanofibers as efficient photocatalysts for the degradation of gas-phase diethylsulfide
Dong et al. Efficient and durable visible light photocatalytic performance of porous carbon nitride nanosheets for air purification
Ke et al. Facile fabrication of CdS-metal-organic framework nanocomposites with enhanced visible-light photocatalytic activity for organic transformation
Al-Hajji et al. Construction of mesoporous g-C3N4/TiO2 nanocrystals with enhanced photonic efficiency
Xiang et al. Graphene-based semiconductor photocatalysts
Jourshabani et al. In situ fabrication of SnO2/S-doped g-C3N4 nanocomposites and improved visible light driven photodegradation of methylene blue
Lu et al. Manganese Oxides Supported on TiO2–Graphene Nanocomposite Catalysts for Selective Catalytic Reduction of NO x with NH3 at Low Temperature
Zhou et al. Enhancement of visible-light photocatalytic activity of mesoporous Au-TiO 2 nanocomposites by surface plasmon resonance
Biswal et al. Rationally designed Ti3C2/N, S-TiO2/g-C3N4 ternary heterostructure with spatial charge separation for enhanced photocatalytic hydrogen evolution
Wang et al. Synchronous surface hydroxylation and porous modification of g-C3N4 for enhanced photocatalytic H2 evolution efficiency
Chakraborty et al. Fabrication of Bi2O3/TiO2 nanocomposites and their applications to the degradation of pollutants in air and water under visible-light
Zheng et al. TiO 2/Ti 3 C 2 intercalated with gC 3 N 4 nanosheets as 3D/2D ternary heterojunctions photocatalyst for the enhanced photocatalytic reduction of nitrate with high N 2 selectivity in aqueous solution
EP2560754A1 (en) Composite grapheno-metal oxide platelet method of preparation and applications
Alhaddad et al. Bi2O3/g-C3N4 nanocomposites as proficient photocatalysts for hydrogen generation from aqueous glycerol solutions beneath visible light

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10805644

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2010805644

Country of ref document: EP