CN114059093B - Zn-doped CoP@MXene/NF composite material and synthetic method and application thereof - Google Patents
Zn-doped CoP@MXene/NF composite material and synthetic method and application thereof Download PDFInfo
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Abstract
The invention relates to a Zn-doped CoP@MXene/NF composite material, a synthesis method and application thereof, wherein the composite material is prepared by the following method: dispersing inorganic salt in strong acid, adding titanium aluminum carbide, etching, adding water, centrifuging and drying to obtain MXene, dispersing MXene in water to obtain a colloid solution, immersing foam nickel in the colloid solution, and drying to obtain an MXene/NF composite material; soaking the MXene/NF composite material in a mixed solution containing an accelerator and a cobalt source, reacting, washing and drying to obtain a Co-MOF@MXene/NF composite material, soaking the composite material in an ethanol water solution containing a zinc source, reacting, washing and drying to obtain a ZnCo-LDH@MXene/NF composite material; and (3) taking the ZnCo-LDH@MXene/NF composite material to carry out a separation type gas phosphating reaction, thus obtaining the target product. Compared with the prior art, the composite material has excellent HER performance and OER performance, low cost and difficult falling.
Description
Technical Field
The invention belongs to the technical field of integral water splitting, and relates to a Zn-doped CoP@MXene/NF composite material, and a synthetic method and application thereof.
Background
Climate change and energy crisis are becoming increasingly of concern, and a great deal of research has been conducted into alternative energy storage and conversion systems. Hydrogen energy is hopeful to become a main source of future energy supply due to the characteristics of sustainability and ecology friendliness. Water splitting electrolysis is considered to be an effective technique for producing hydrogen. Typically, the water splitting reaction comprises two half reactions: hydrogen Evolution Reactions (HER) and Oxygen Evolution Reactions (OER). The platinum-based material in the noble metal-based material is a reference catalyst for reducing the HER overpotential, and the iridium-based or ruthenium-based material is a reference catalyst for reducing the OER overpotential. However, the high cost and scarcity severely limit its large-scale application. Therefore, it is urgent to find a catalyst having excellent activity and durability, low cost, and sufficient reserves of raw materials for HER and OER.
Compounds of transition metal carbides, sulfides, phosphides, nitrides, and the like have been developed to replace noble metal-based materials. Wherein transition metal-based phosphides (TMPs), e.g. FeP, coP, ni 2 P、Cu 3 P, znP and WP have been widely studied due to their non-noble nature and unique activity on HER. Among them, cobalt-based phosphide, nickel-based phosphide and iron-based phosphide exhibit electrocatalytic activity to OER in addition to having catalytic activity to HER. Therefore, the dual-function electrocatalyst developed by using TMPs as materials has application prospect, can work in the same electrolyte and has lower cost. However, the electrocatalytic properties of TMPs are still far from satisfactory due to the inherent poor conductivity of TMPs.
Mxnes is a new family of two-dimensional (2D) based on transition metal carbides or nitrides, which attracts more and more attention due to its excellent electrical conductivity as well as metallic conductivity, and is one of the focus in the electrochemical energy storage and conversion fields. MXenes have good surface hydrophilicity and mechanical stability, while having a highly active surface, and are easy to adjust, and MXenes can be used for bulk water decomposition. Thus, it is highly desirable to couple mxnes with bifunctional active catalysts to increase HER and OER activity, however, reports on mxnes-based heterostructures as effective bifunctional electrocatalysts for bulk water splitting are very limited, studies on compositing mxnes with TMPs for bulk water splitting have not been reported, and developing a catalyst with excellent HER activity as well as OER activity based on mxnes and TMPs has been challenging.
The use of catalysts in the form of powders for electrocatalysis requires the deposition of the powdered catalyst on the electrode by the addition of a binder such as polyvinylidene fluoride (PVDF) or Nafion. The binder largely impedes contact between the electrocatalyst and the electrolyte, thereby reducing the catalytic activity of the catalyst. In addition, the powdered catalyst may fall off from the electrode during the electrochemical process, resulting in poor catalytic performance.
Disclosure of Invention
The invention aims to provide a Zn-doped CoP@MXene/NF composite material and a synthetic method and application thereof, so as to overcome the defects of poor overall water decomposition capacity, higher cost, limited catalytic activity of a powder catalyst, easy falling-off and the like of a bifunctional catalyst in the prior art.
The aim of the invention can be achieved by the following technical scheme:
one of the technical schemes of the invention provides a synthesis method of a Zn-doped CoP@MXene/NF composite material, which comprises the following steps:
(1) Dispersing inorganic salt in strong acid, adding titanium aluminum carbide, etching, adding water, centrifuging for multiple times, and drying to obtain MXene;
(2) Dispersing the obtained MXene in water to obtain an MXene colloidal solution, immersing foam nickel in the MXene colloidal solution, and then drying to obtain an MXene/NF composite material;
(3) Mixing an accelerator with a cobalt source to obtain a mixed solution, soaking the obtained MXene/NF composite material in the mixed solution, and carrying out reaction, washing and drying to obtain a Co-MOF@MXene/NF composite material;
(4) Immersing the obtained Co-MOF@MXene/NF composite material into an ethanol water solution containing a zinc source, and carrying out reaction, washing and drying to obtain the ZnCo-LDH@MXene/NF composite material;
(5) And (3) taking the obtained ZnCo-LDH@MXene/NF composite material to carry out a separation type gas phosphating reaction, thus obtaining the target product.
Further, in the step (1), the inorganic salt is lithium fluoride, and the strong acid is hydrochloric acid.
Further, the concentration of the hydrochloric acid is 9M, and the addition amount ratio of the lithium fluoride, the hydrochloric acid and the titanium aluminum carbide is 1.6g to 20mL to 1g.
Further, in the step (1), the etching temperature is 20-40 ℃ and the etching time is 20-30 h.
Further, in the step (1), the specific steps of multiple centrifugation are as follows:
(1) After adding water, centrifuging twice, and discarding supernatant obtained by each centrifugation; centrifuging for three times, and collecting supernatant obtained by each centrifuging to obtain single-layer or multi-layer MXene water suspension;
(2) The resulting aqueous MXene suspension was purged with nitrogen and then centrifuged to collect the precipitate, thus completing the centrifugation.
Further, in the step (1), the centrifugal speed is 3000r/min, and the centrifugal time is 5-10min each time.
Further, in the step (2), nitrogen was continuously introduced for 30 minutes.
Further, in the step (2), the centrifugal speed is 10000r/min, and the centrifugal time is 30min.
Further, in the step (1), after centrifugation, MXene is obtained by freeze-drying.
Further, in the step (2), the concentration of the MXene colloidal solution is 1-4 mg/mL.
In the step (2), the soaking time of the foam nickel in the MXene colloidal solution is 1-3 h.
Further, in the step (3), the accelerator is a 0.4M 2-methylimidazole aqueous solution, the cobalt source is a 50mM cobalt nitrate hexahydrate aqueous solution, the size of the MXene/NF composite material is 1cm×2cm×2.5mM, and the amounts of the 2-methylimidazole aqueous solution and the cobalt nitrate hexahydrate aqueous solution added are 40mL and 40mL respectively.
Further, in the step (3), the reaction time is 3 to 5 hours.
Further, in the step (3), washing is performed using water.
Further, in the step (4), the zinc source is zinc nitrate hexahydrate, and the volume ratio of ethanol to water in the ethanol aqueous solution is 1: the Co-MOF@MXene/NF composite material has the size of 1cm x 2cm x 2.5mm, and the corresponding amounts of added zinc nitrate hexahydrate and ethanol aqueous solution are respectively 0.5mmol and 100mL.
Further, in the step (4), the reaction temperature is 60-90 ℃ and the reaction time is 10-20 min.
Further, in the step (2), the drying temperature was 60℃and the drying time was 12 hours.
Further, in the step (2), the foam nickel is also subjected to pretreatment before being added, and the pretreatment process is as follows:
the foam nickel matrix is cut into samples with the required size, then the samples are soaked in hydrochloric acid, then acetone is used for ultrasonic treatment, ethanol and water are used for circulating ultrasonic treatment for a plurality of times, and finally vacuum drying is carried out overnight.
Further, the concentration of the hydrochloric acid is 3M, and the soaking time in the hydrochloric acid solution is 30min.
Further, the sonication time in acetone was 15min.
Further, the temperature of vacuum drying was 60 ℃.
Further, in the step (4), the washing is repeated using ethanol and water.
Further, in the step (4), the drying temperature was 60 ℃.
Further, in the step (5), the separated gasThe phosphating agent used in the bulk phosphating reaction is NaH 2 PO 2 And (3) powder.
Further, the ZnCo-LDH@MXene/NF composite material and NaH 2 PO 2 The mass ratio of the powder is 1:20.
further, in the step (5), in the separated gas phosphating reaction, the annealing temperature is 100-350 ℃, the heat preservation time is 2 hours, and the heating rate is 1-3 ℃/min.
Further, in the step (5), the flow rate of the inert gas during the separated gas phosphating reaction is 300sccm.
Further, the inert gas is nitrogen.
The second technical scheme of the invention provides a Zn-doped CoP@MXene/NF composite material, which is prepared by the synthesis method.
Further, the composite material comprises a Zn-CoP nano sheet, an MXene substrate and foam nickel, wherein the MXene substrate is attached to the foam nickel, and the Zn-CoP nano sheet is attached to the MXene substrate.
Still further, the Zn-CoP nanoplatelets are hollow, and the Zn-CoP nanoplatelet array is distributed on the MXene substrate.
The third technical scheme of the invention provides application of the composite material, and the composite material can be applied to electrocatalytic overall water decomposition reaction, and is particularly suitable for electrocatalytic overall water decomposition in alkaline solution.
Further, when the composite material is used for the electrocatalytic overall water splitting reaction, the composite material is used as a working electrode in the electrocatalytic overall water splitting reaction, a potassium hydroxide solution without air is used as an electrolyte, an Ag/AgCl electrode is used as a reference electrode, and a platinum wire electrode is used as a counter electrode, and the specific steps are as follows:
the Zn-dopped CoP@MXene/NF composite material, the Ag/AgCl electrode and the platinum wire electrode are connected with an electrochemical workstation, and the electrocatalytic performance of the Zn-dopped CoP@MXene/NF composite material is tested in a potassium hydroxide solution.
Further, the concentration of the potassium hydroxide solution was 1.0M.
Further, nitrogen gas was introduced into the potassium hydroxide solution to expel air from the potassium hydroxide solution, thereby obtaining an air-free potassium hydroxide solution.
Further, the nitrogen gas was introduced for 30 minutes.
Further, the surface of the Zn-doped CoP@MXene/NF composite material is cleaned by the potassium hydroxide solution before the Zn-doped CoP@MXene/NF composite material is used.
The cobalt source in the invention can provide Co for the generation of target products 2+ Co-MOF put into Zn (NO 3 ) 2 ·6H 2 In O solution, water is dissolved to generate H + And OH (OH) - ，H + Promoting Co-MOF etching to Co 2+ ，OH - Promote Zn 6+ ，Co 2+ And (3) precipitating to form ZnCo-LDH, and completely etching Co-MOF along with hydrolysis to form a hollow nano array structure, wherein the surface of the hollow nano array structure is grown with small nano sheets. After Zn doping, the P-bit 3P orbit moves upwards, so that the filling reverse bond state of the H1s orbit is reduced, the H-P bond is enhanced, and the composite material and H are promoted 2 O contact ability, increasing the HER performance of the material. Meanwhile, zn-CoP can be converted into CoOOH in situ in the reaction process, so that the OER performance of the composite material is enhanced.
In the Zn-doped CoP@MXene/NF composite material, zn-doped CoP grows on an MXene/NF substrate to form a layered 3D porous structure with large specific surface area and high conductivity. The foam nickel is used as sound absorption porous metal with excellent three-dimensional full-through mesh structure performance, nickel frameworks are hollow and are mutually connected in a metallurgical state, and the foam nickel has the advantages of good stability, high porosity, thermal shock resistance, small bulk density, large specific surface area and the like, and more importantly, the foam nickel can avoid using adhesive additives, further improves the contact capability of a composite material with water, and is beneficial to the catalyst to fully exert catalytic activity; the MXene prepared by etching the MAX phase has good conductivity and hydrophilicity, and has larger surface area and adjustable structure. The Zn-doped CoP@MXene/NF composite material provided by the invention has excellent adsorption capacity on a hydrogen intermediate in an alkaline solution, so that excellent catalytic performance is shown, hydrogen is easier to prepare, and meanwhile, adsorption and desorption of oxygen are promoted, so that the Zn-doped CoP@MXene/NF composite material has excellent overall water decomposition capacity.
The high-performance catalyst is prepared through the design of the nano/microstructure, the preparation flow is simpler, and the prepared Zn-doped CoP@MXene/NF composite material has a hollow and porous structure. In the composite material, a hollow Zn-CoP nano array is grown on NF of a load MXene substrate, and the hollow Zn-CoP nano array is derived from a metal-organic framework (MOF) precursor and can be directly used as a high-activity and durable hydrogen evolution electrocatalyst. Zn-CoP arrays can also be converted to Zn-CoOOH in situ with enhanced OER performance. The Zn-CoP array reduces the energy barrier through Zn doping, promotes electrolyte permeation and promotes release of precipitated bubbles, thereby ensuring high conductivity of the composite material.
The combination of Zn-doped CoP and natural conductive material MXene in the composite material of the invention forms strong synergistic chemical and electronic coupling, and Zn doping modifies the electronic structure of the composite material so as to exert the advantages and functions of the catalyst component to the greatest extent. The composite material can be used as an anode and a cathode to realize high-efficiency integral water decomposition reaction.
In the process of preparing the MXene, al atoms are selectively removed through multiple centrifugation, so that a single-layer or multi-layer MXene aqueous suspension is obtained. The Zn-CoP is obtained by phosphating under the inert gas atmosphere through an annealing process. The invention limits the technological conditions in the reaction process, such as annealing temperature, heating rate and the like, and can obtain products with better crystallinity within a limited range, namely, the performance of the products can be optimized.
Compared with the prior art, the invention has the following advantages:
(1) The Zn-doped CoP@MXene/NF composite material provided by the invention has good HER performance and OER performance, and has the advantages of lower energy barrier required to be broken through for hydrogen evolution and oxygen evolution, higher conversion rate and higher speed;
(2) The Zn-doped CoP@MXene/NF composite material is lower than the synthesis cost of most catalysts, the raw materials of the catalysts can be purchased, the earth reserve is sufficient, and the Zn-doped CoP@MXene/NF composite material is not related to the explosive and toxic drugs;
(3) In the Zn-doped CoP@MXene/NF composite material, the MXene substrate is attached to the foam nickel, and the Zn-CoP nano sheets are distributed on the MXene substrate, so that an adhesive is avoided, the contact capacity of the composite material with water is further improved, the composite material is not easy to fall off, and the full play of catalytic activity is facilitated.
Drawings
FIG. 1 is a graph showing the HER overpotential performance of the Zn-doped CoP@MXene/NF composite material, and ZnCo-LDH@MXene/NF obtained in example 1, comparative example 1, and comparative example 2, respectively;
FIG. 2 is a graph showing the comparison of the OER overpotential performance of the Zn-doped CoP@MXene/NF composite material, coP@MXene/NF composite material and ZnCo-LDH@MXene/NF obtained in example 1, comparative example 1 and comparative example 2, respectively.
Detailed Description
The invention will now be described in detail with reference to the drawings and specific examples. The present embodiment is implemented on the premise of the technical scheme of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following examples.
In the following examples, unless otherwise indicated, the starting materials or processing techniques are all conventional commercially available in the art.
In the following examples, nickel foam was used commercially from Kunsland Weidas electronics Inc.
In the following examples, the pretreatment process of the foam nickel is as follows:
the nickel foam matrix was cut into 1cm x 2cm x 2.5mm samples, which were then immersed in 3M hydrochloric acid for 30min, sonicated with acetone for 15min, sonicated with ethanol, water circulation for several times, and finally vacuum dried at 60 ℃ overnight.
Example 1:
the raw materials for preparing the Zn-cooled CoP@MXene/NF composite material in this example are as follows:
hydrochloric acid (9M, 20 mL)
Lithium fluoride (1.6 g)
Titanium aluminum carbide (1 g)
2-methylimidazole aqueous solution (0.4M, 40 mL)
Cobalt nitrate hexahydrate aqueous solution (50 mM,40 mL)
Zinc nitrate hexahydrate (0.5 mmol)
Aqueous ethanol (ethanol to water volume ratio 1:4, 100 mL)
Sodium hypophosphite
A Zn-doped CoP@MXene/NF composite material is prepared by a preparation method comprising the following steps:
(a) Hydrochloric acid (9M, 20 mL) was taken, 1.6g of lithium fluoride was added to a polypropylene (PP) rubber bottle and magnetically stirred for 5 minutes. Then 1g of titanium aluminum carbide was slowly added and etching was performed for 24 hours at 35℃in an oil bath. After the etching was completed, 140ml of deionized water was added to the PP rubber bottle, and then the PP rubber bottle was gently shaken and the contents were transferred to 4 centrifuge tubes and centrifuged at 3000r/min for 5min. The supernatant from the previous two centrifuges is discarded, and then the third, fourth and fifth centrifuges are performed, and the supernatant from the third, fourth and fifth centrifuges is collected to obtain single-layer or multi-layer MXene aqueous suspension. Then N is added 2 Blowing into the collected MXene aqueous suspension for 30min, centrifuging at 10000r/min for half an hour, collecting precipitate, and freeze-drying to obtain MXene. In use, MXene is dispersed in water to form a MXene colloidal solution (4 mg/mL);
(b) Immersing a piece of pretreated foam nickel in an MXene colloidal solution to enable the foam nickel to be rapidly adsorbed on the surface of the foam nickel, taking out the foam nickel after 1h, and vacuum drying the foam nickel at 60 ℃ for 12h to obtain an MXene/NF composite material;
(c) Rapidly pouring 2-methylimidazole aqueous solution (0.4M, 40 mL) into cobalt nitrate hexahydrate aqueous solution (50 mM,50 mL) to obtain a mixed solution, immersing one piece of MXene/NF composite material into the mixed solution, reacting for 4 hours, taking out a sample, washing with deionized water and overnight at 60 ℃ to obtain a Co-MOF@MXene/NF composite material;
(d) Preparing a ZnCo-LDH array on a Co-MOF@MXene/NF composite material, immersing a piece of Co-MOF@MXene/NF composite material into an ethanol aqueous solution (ethanol to water volume ratio of 1:4, 100 mL) containing zinc nitrate hexahydrate (0.5 mmol), reacting at 85 ℃ for 15 minutes, removing purple of the Co-MOF, taking out a sample, repeatedly washing with ethanol and water, and drying at 60 ℃ to obtain the ZnCo-LDH@MXene/NF composite material;
(e) Finally preparing a nano matrix Zn-CoP: a piece of ZnCo-LDH@MXene/NF composite material and NaH 2 PO 2 Powder (20 times of the mass of ZnCo-LDH@MXene/NF composite material) is placed at two different positions of a ceramic boat, naH 2 PO 2 And heating to 350 ℃ at a heating rate of 2 ℃/min under a nitrogen atmosphere at the upstream side of the tube furnace, and preserving heat for 2 hours, wherein the nitrogen flow rate is 300sccm, and obtaining the target product Zn-doped CoP@MXene/NF composite material after the reaction.
The Zn-dopped CoP@MXene/NF composite material is directly used as a working electrode in the electrocatalytic integral water decomposition reaction, and the specific steps are as follows:
(1) The Zn-doped CoP@MXene/NF composite material is directly used as a working electrode in the electrocatalytic overall water decomposition reaction;
(2) Preparing 1.0M potassium hydroxide solution as an electrocatalytic electrolyte, introducing nitrogen to drive out air, then respectively taking a Zn-doped CoP@MXene/NF composite material, an Ag/AgCl electrode and a platinum wire electrode as a working electrode, a reference electrode and a counter electrode, connecting the working electrode, the reference electrode and the counter electrode to an electrochemical workstation, and measuring the electrocatalytic performance of the electrode material in the electrolyte.
The test results are shown in fig. 1 and 2, respectively. As can be seen from FIG. 1, when the current density is 10mA/cm 2 When the Zn-doped CoP@MXene/NF composite material is used, the hydrogen evolution overpotential is 142mV; as can be seen from FIG. 2, when the current density is 10mA/cm 2 When the Zn-doped CoP@MXene/NF composite material is used, the oxygen evolution overpotential is 310mV.
Example 2:
most of the same as in example 1 except that in this example, the temperature was increased to 350℃at a heating rate of 2℃per minute, and was changed to 100℃at a heating rate of 1℃per minute.
Example 3:
most of the same as in example 1, except that in this example, the temperature was increased to 350℃at a heating rate of 2℃per minute, and was changed to 200℃at a heating rate of 3℃per minute.
Example 4:
most of the same as in example 1 except that in this example, the etching was performed under the oil bath condition of 35℃for 24 hours, and the etching was performed under the oil bath condition of 20℃for 20 hours.
Example 5:
most of the same as in example 1 except that in this example, the etching was performed under the oil bath condition of 35℃for 24 hours, and the etching was performed under the oil bath condition of 40℃for 30 hours.
Example 6:
most of the same as in example 1, except that in this example, the MXene colloidal solution (4 mg/mL) was changed to the MXene colloidal solution (1 mg/mL).
Example 7:
most of the same as in example 1, except that in this example, the MXene colloidal solution (4 mg/mL) was changed to the MXene colloidal solution (3 mg/mL).
Example 8:
most of the same as in example 1 except that in this example, the sample was taken out after 1 hour and dried under vacuum at 60℃for 12 hours, changed to 3 hours, and then taken out and dried under vacuum at 60℃for 12 hours.
Example 9:
most of the same as in example 1 except that in this example, the sample was taken out after 1 hour and dried under vacuum at 60℃for 12 hours, changed to 2 hours, and then taken out and dried under vacuum at 60℃for 12 hours.
Example 10:
most of them are the same as in example 1 except that in this example, the reaction in step (c) was changed to the reaction for 3 hours after the reaction for 4 hours.
Example 11:
most of the same as in example 1 except that in this example, the reaction was carried out for 4 hours in the step (c) and then for 5 hours.
Example 12:
in the present example, the reaction was carried out at 85℃for 15 minutes, and then at 60℃for 10 minutes, except that the reaction was carried out at 85℃for 15 minutes in step (d) in the present example.
Example 13:
in the present example, the reaction was carried out at 85℃for 15 minutes, and then at 90℃for 20 minutes, except that the reaction was carried out at 85℃for 15 minutes in step (d) in the present example.
Comparative example 1:
most of the same as in example 1, except that the addition of zinc nitrate hexahydrate, i.e. no Zn doping, was omitted.
Raw materials for preparing CoP@MXene/NF composite material:
hydrochloric acid (9M, 20 mL)
Lithium fluoride (1.6 g)
Titanium aluminum carbide (1 g)
2-methylimidazole aqueous solution (0.4M, 40 mL)
Cobalt nitrate hexahydrate aqueous solution (50 mM,40 mL)
Zinc nitrate hexahydrate 0.5mmol
Sodium hypophosphite
The CoP@MXene/NF composite material is prepared by a preparation method comprising the following steps of:
(a) 20mL (9M) of hydrochloric acid was taken, 1.6g of lithium fluoride was added to a polypropylene rubber bottle and magnetically stirred for 5 minutes. Then 1g of titanium aluminum carbide was slowly added and etching was performed for 24 hours at 35℃in an oil bath. After etching was completed, 140ml of deionized water was added to the PVP bottle, and the bottle was gently shaken and transferred to 4 centrifuge tubes. Centrifuging at 3000r/min for 5min, discarding supernatant, centrifuging for the third, fourth and fifth times, and collecting supernatant after centrifuging for the third, fourth and fifth times to obtain single-layer or multi-layer Xene water suspension. N2 was then blown into the collected MXene aqueous suspension for 30min, and then centrifuged at 10000r/min for half an hour, the precipitate was collected and freeze-dried. When in use, the composition is dispersed in water to form a colloid solution (4 mg/mL);
(b) Then taking a piece of pretreated foam nickel, immersing the foam nickel in an MXene colloidal solution to enable the foam nickel to be rapidly adsorbed on the surface of the foam nickel, taking out the foam nickel after 1h, and vacuum drying the foam nickel at 60 ℃ for 12h to obtain an MXene/NF composite material;
(c) A0.4M aqueous 2-methylimidazole solution was quickly poured into a 50mM aqueous cobalt nitrate hexahydrate solution, and then a piece of the MXene/NF composite material was immersed in the above mixed solution. After 4h of reaction, taking out a sample, washing with deionized water and drying at 60 ℃ overnight to obtain a Co-MOF@MXene/NF composite material;
(d) Finally preparing a nano matrix CoP: a piece of Co-MOF@MXene/NF composite material and NaH 2 PO 2 Powder (20 times of Co-MOF@MXene/NF composite material) was placed in two different positions of a ceramic boat, naH 2 PO 2 Located on the upstream side of the tube furnace. The temperature was raised to 350℃under a nitrogen atmosphere at a heating rate of 2℃per minute, and the temperature was maintained for 2 hours at a nitrogen flow rate of 300sccm. And (3) obtaining the target product CoP@MXene/NF composite material after the reaction is finished.
The CoP@MXene/NF composite material is directly used as a working electrode in the electrocatalytic overall water decomposition reaction, and the specific steps are as follows:
(1) The CoP@MXene/NF composite material is directly used as a working electrode in the electrocatalytic overall water decomposition reaction;
(2) Preparing 1.0M potassium hydroxide solution as an electrocatalytic electrolyte, introducing nitrogen to drive out air, then respectively taking a CoP@MXene/NF composite material, an Ag/AgCl electrode and a platinum wire electrode as a working electrode, a reference electrode and a counter electrode, connecting the working electrode, the reference electrode and the counter electrode to an electrochemical workstation, and measuring the electrocatalytic performance of the electrode material in the electrolyte.
As shown in FIG. 1, when the current density is 10mA/cm 2 When the hydrogen evolution overpotential of the CoP@MXene/NF composite material is 260mV; as shown in FIG. 2, when the current density is 10mA/cm 2 When the oxygen evolution overpotential of the CoP@MXene/NF composite material is 320mV. Compared with the Zn-doped CoP@MXene/NF composite material, the HER performance and OER performance of the CoP@MXene/NF composite material are obviously deteriorated due to the fact that the CoP@MXene/NF composite material is not doped with Zn, so that the conductivity of the material is greatly reduced, and the electrocatalytic performance of the material is further reduced.
Comparative example 2:
most of the same as in example 1, except that the addition of sodium hypophosphite was omitted, i.e., no phosphating was performed, which would greatly reduce the electrochemical performance of the material.
Preparation of ZnCo-LDH@MXene/NF composite material
Raw materials:
hydrochloric acid (9M, 20 mL)
Lithium fluoride (1.6 g)
Titanium aluminum carbide (1 g)
2-methylimidazole aqueous solution (0.4M, 40 mL)
Cobalt nitrate hexahydrate aqueous solution (50 mM,40 mL)
Zinc nitrate hexahydrate (0.5 mmol)
The ZnCo-LDH@MXene/NF composite material is prepared by a preparation method comprising the following steps of:
(a) 20mL (9M) of hydrochloric acid was taken, 1.6g of lithium fluoride was added to a polypropylene rubber bottle and magnetically stirred for 5 minutes. Then 1g of titanium aluminum carbide was slowly added and etching was performed for 24 hours at 35℃in an oil bath. After etching was completed, 140ml of deionized water was added to the PVP bottle, and the bottle was gently shaken and transferred to 4 centrifuge tubes. Centrifuging at 3000r/min for 5min, discarding supernatant, centrifuging for the third, fourth and fifth times, and collecting supernatant after centrifuging for the third, fourth and fifth times to obtain single-layer or multi-layer Xene water suspension. N2 was then blown into the collected MXene aqueous suspension for 30min, and then centrifuged at 10000r/min for half an hour, the precipitate was collected and freeze-dried. When in use, the solution is dispersed in water to form MXene colloidal solution (4 mg/mL);
(b) Then taking a piece of pretreated foam nickel, immersing the foam nickel in an MXene colloidal solution to enable the foam nickel to be rapidly adsorbed on the surface of the foam nickel, taking out the foam nickel after 1h, and vacuum drying the foam nickel at 60 ℃ for 12h to obtain an MXene/NF composite material;
(c) A0.4M aqueous 2-methylimidazole solution was quickly poured into a 50mM aqueous cobalt nitrate hexahydrate solution, and then a piece of the MXene/NF composite material was immersed in the above mixed solution. After 4h of reaction, taking out a sample, washing with deionized water and drying at 60 ℃ overnight to obtain a Co-MOF@MXene/NF composite material;
(d) Then preparing a ZnCo-LDH array on a Co-MOF@MXene/NF composite material: a piece of the Co-MOF@MXene/NF composite was immersed in an aqueous ethanol solution (volume ratio of ethanol to water 1:4, 100 mL) containing zinc nitrate hexahydrate (0.5 mmol). After 15 minutes of reaction at 85 ℃, the purple color of the Co-MOF disappears, then the sample is taken out, repeatedly washed with ethanol and water, and dried at 60 ℃ to obtain the ZnCo-LDH@MXene/NF composite material.
The ZnCo-LDH@MXene/NF composite material is directly used as a working electrode in the electrocatalytic overall water decomposition reaction, and the specific steps are as follows:
(1) The ZnCo-LDH@MXene/NF composite material is directly used as a working electrode in the electrocatalytic overall water decomposition reaction;
(2) Preparing 1.0M potassium hydroxide solution as an electrocatalytic electrolyte, introducing nitrogen to drive out air, then respectively taking a ZnCo-LDH@MXene/NF composite material, an Ag/AgCl electrode and a platinum wire electrode as a working electrode, a reference electrode and a counter electrode, connecting the working electrode, the reference electrode and the counter electrode to an electrochemical workstation, and measuring the electrocatalytic performance of the electrode material in the electrolyte.
As shown in FIG. 1, when the current density is 10mA/cm 2 When the hydrogen evolution overpotential of the ZnCo-LDH@MXene/NF composite material is 320mV; as shown in FIG. 2, when the current density is 10mA/cm 2 When the oxygen evolution overpotential of the ZnCo-LDH@MXene/NF composite material is 390mV. Compared with the Zn-doped CoP@MXene/NF composite material, the HER performance and OER performance of the ZnCo-LDH@MXene/NF composite material are obviously deteriorated, and the HER performance and OER performance of the ZnCo-LDH@MXene/NF composite material are attributed to the fact that the composite material is not phosphated and does not contain CoP nano sheets grown in an array, so that the conductivity of the material is greatly reduced, and the electrocatalytic performance of the material is further reduced.
The previous description of the embodiments is provided to facilitate a person of ordinary skill in the art in order to make and use the present invention. It will be apparent to those skilled in the art that various modifications can be readily made to these embodiments and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above-described embodiments, and those skilled in the art, based on the present disclosure, should make improvements and modifications without departing from the scope of the present invention.
Claims (10)
1. A method for synthesizing a Zn-doped CoP@MXene/NF composite material is characterized by comprising the following steps of:
(1) Dispersing inorganic salt in strong acid, adding titanium aluminum carbide, etching, adding water, centrifuging for multiple times, and drying to obtain MXene;
(2) Dispersing the obtained MXene in water to obtain an MXene colloidal solution, immersing foam nickel in the MXene colloidal solution, and then drying to obtain an MXene/NF composite material;
(3) Mixing an accelerator with a cobalt source to obtain a mixed solution, soaking the obtained MXene/NF composite material in the mixed solution, and carrying out reaction, washing and drying to obtain a Co-MOF@MXene/NF composite material;
(4) Immersing the obtained Co-MOF@MXene/NF composite material into an ethanol water solution containing a zinc source, and carrying out reaction, washing and drying to obtain the ZnCo-LDH@MXene/NF composite material;
(5) And (3) taking the obtained ZnCo-LDH@MXene/NF composite material to carry out a separation type gas phosphating reaction, thus obtaining the target product.
2. The method for synthesizing a Zn-doped CoP@MXene/NF composite material according to claim 1, wherein in the step (1), the inorganic salt is lithium fluoride, and the strong acid is hydrochloric acid;
the concentration of the hydrochloric acid is 9M, and the addition amount ratio of the lithium fluoride, the hydrochloric acid and the titanium aluminum carbide is 1.6g:20mL:1g.
3. The method for synthesizing the Zn-doped CoP@MXene/NF composite material according to claim 1, wherein in the step (1), the etching temperature is 20-40 ℃ and the etching time is 20-30 h.
4. The method for synthesizing the Zn-doped CoP@MXene/NF composite material according to claim 1, wherein in the step (2), the concentration of the MXene colloidal solution is 1-4 mg/mL;
the soaking time of the foam nickel in the MXene colloidal solution is 1-3 h.
5. The method for synthesizing the Zn-doped CoP@MXene/NF composite material according to claim 4, wherein in the step (3), the promoter is 0.4M 2-methylimidazole aqueous solution, the cobalt source is 50mM cobalt nitrate hexahydrate aqueous solution, the size of the MXene/NF composite material is 1cm x 2cm x 2.5mM, and the amounts of the added 2-methylimidazole aqueous solution and the added cobalt nitrate hexahydrate aqueous solution are 40mL and 40mL respectively;
in the step (3), the reaction time is 3-5 h.
6. The method for synthesizing a Zn-doped CoP@MXene/NF composite material according to claim 5, wherein in the step (4), the zinc source is zinc nitrate hexahydrate, and the volume ratio of ethanol to water in the ethanol aqueous solution is 1: the Co-MOF@MXene/NF composite material has the size of 1cm x 2cm x 2.5mm, and the corresponding amounts of added zinc nitrate hexahydrate and ethanol aqueous solution are respectively 0.5mmol and 100mL;
in the step (4), the reaction temperature is 60-90 ℃ and the reaction time is 10-20 min.
7. The method for synthesizing a Zn-doped CoP@MXene/NF composite material according to claim 1, wherein in the step (5), a phosphating agent used in the separated gas phosphating reaction is NaH 2 PO 2 A powder;
in the step (5), the ZnCo-LDH@MXene/NF composite material and NaH 2 PO 2 The mass ratio of the powder is 1:20.
8. the method for synthesizing the Zn-doped CoP@MXene/NF composite material according to claim 1, wherein in the step (5), in the separated gas phosphating reaction, the annealing temperature is 100-350 ℃, the heat preservation time is 2 hours, and the heating rate is 1-3 ℃/min.
9. A Zn-doped cop@mxene/NF composite material characterized in that it is prepared by the synthetic method according to any one of claims 1-8.
10. The use of a Zn-cooled cop@mxene/NF composite material according to claim 9, characterized in that the composite material is applied to electrocatalytic bulk water splitting reactions.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113096972A (en) * | 2021-04-12 | 2021-07-09 | 上海理工大学 | Preparation method of MXene/NiCoP/NF composite material |
| CN113638002A (en) * | 2021-07-14 | 2021-11-12 | 上海应用技术大学 | FeCo LDH/Ti3C2MXene/NF composite material and preparation method and application thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113096972A (en) * | 2021-04-12 | 2021-07-09 | 上海理工大学 | Preparation method of MXene/NiCoP/NF composite material |
| CN113638002A (en) * | 2021-07-14 | 2021-11-12 | 上海应用技术大学 | FeCo LDH/Ti3C2MXene/NF composite material and preparation method and application thereof |
Non-Patent Citations (2)
| Title |
|---|
| Liang Yan et. al..A general approach to the synthesis of transition metal phosphide nanoarrays on MXene nanosheets for pH-universal hydrogen evolution and alkaline overall water splitting.《J. Mater. Chem. A》.2020,第第8卷卷第14234页. * |
| Tingting Liu et. al..Enhanced Electrocatalysis for Energy-Efficient Hydrogen Production over CoP Catalyst with Nonelectroactive Zn as a Promoter.《Adv. Energy Mater.》.2017,第第7卷卷第1700020页. * |
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