阅读说明：本技术 一种具有介孔结构的碳掺杂wp纳米片电催化剂及其制备方法 (Carbon-doped WP nanosheet electrocatalyst with mesoporous structure and preparation method thereof ) 是由 刘勇平 刘威 吕慧丹 耿鹏 庄杨 王子良 于 2020-05-08 设计创作，主要内容包括：本发明提供了一种具有介孔结构的碳掺杂WP纳米片电催化剂制备方法,包括以下步骤：(1)制备片层WO<Sub>3</Sub>·2H<Sub>2</Sub>O粉末：(2)WO<Sub>3</Sub>/胺类物质杂化物前驱体粉末的制备：取WO<Sub>3</Sub>·2H<Sub>2</Sub>O块状粉末和胺类物质加入到聚四氟乙烯反应釜中在100-200℃下反应24-72h得到白色沉淀,用乙醇离心清洗数次,然后干燥得到WO<Sub>3</Sub>/胺类物质杂化物前驱体白色固体粉末；(3)WP@C的制备：以次亚磷酸钠作为磷源,使用双温控真空气氛管式炉先使WO<Sub>3</Sub>/胺类物质杂化物前驱体分解为WO<Sub>x</Sub>@C复合物,然后将WO<Sub>x</Sub>@C复合物磷化还原为片状WP@C电催化材料。本发明方法制得的碳掺杂WP纳米片电催化材料具有较高的比表面积和导电性。(The invention provides a preparation method of a carbon-doped WP nanosheet electrocatalyst with a mesoporous structure, which comprises the following steps of: (1) preparation of the sheet WO 3 ·2H 2 O powder: (2) WO 3 Preparation of amine substance hybrid precursor powder: get WO 3 ·2H 2 Adding the O block powder and the amine substance into a polytetrafluoroethylene reaction kettle, reacting for 24-72h at the temperature of 100 ℃ and 200 ℃ to obtain white precipitate, centrifugally cleaning for several times by using ethanol, and then carrying out centrifugal cleaningDrying to obtain WO 3 White solid powder of amine substance hybrid precursor; (3) preparation of WP @ C: sodium hypophosphite is used as a phosphorus source, and a double-temperature-control vacuum atmosphere tube furnace is used for firstly leading WO 3 Decomposition of amine hybrid precursor into WO x @ C complex, then WO x The @ C complex is phosphitylated and reduced to a sheet-like WP @ C electrocatalytic material. The carbon-doped WP nanosheet electrocatalytic material prepared by the method has high specific surface area and electrical conductivity.)

1. A preparation method of a carbon-doped WP nanosheet electrocatalyst with a mesoporous structure is characterized by comprising the following steps of:

(1) preparation of the sheet WO₃·2H₂O powder: mixing Na₂WO₄·2H₂Adding the O solution into the HCl solution for reaction, centrifuging the obtained light yellow suspension after the reaction is finished, washing the light yellow suspension for a plurality of times by using deionized water, and finally drying the obtained light yellow substance by using a freeze dryer to obtain the lamella WO₃·2H₂O block powder;

(2)WO₃preparation of amine substance hybrid precursor powder: get WO₃·2H₂Adding the O block powder and the amine substance into a polytetrafluoroethylene reaction kettle, reacting for 24-72h at the temperature of 100-200 ℃ to obtain white precipitate, centrifugally cleaning the white precipitate for a plurality of times by using ethanol, and drying the white precipitate to obtain WO₃White solid powder of amine substance hybrid precursor;

(3) preparation of WP @ C: sodium hypophosphite is used as a phosphorus source, and a double-temperature-control vacuum atmosphere tube furnace is used for firstly leading WO₃Decomposition of white solid powder of amine substance hybrid precursor into WO_x@ C complex, then WO_xThe @ C complex is phosphitylated and reduced to a sheet-like WP @ C electrocatalytic material.

2. The preparation method of the carbon-doped WP nanosheet electrocatalyst with the mesoporous structure according to claim 1, wherein the concentration of the sodium tungstate solution in step (1) is as follows: 1-3mol/L, hydrochloric acid solution concentration: 2-5 mol/L.

3. The preparation method of the carbon-doped WP nanosheet electrocatalyst with a mesoporous structure according to claim 1, wherein WO is applied to step (2)₃·2H₂Mass of O powder: 0.1-2g, volume of amine substance: 4-80 mL.

4. The preparation method of the carbon-doped WP nanosheet electrocatalyst with the mesoporous structure according to any one of claims 1 to 3, wherein in the step (2), the amine substance is one of n-propylamine, n-butylamine and n-octylamine.

5. The preparation method of the carbon-doped WP nanosheet electrocatalyst with the mesoporous structure according to claim 1, wherein the mass of sodium hypophosphite in step (2) is 1-3 g.

6. The preparation method of the carbon-doped WP nanosheet electrocatalyst with the mesoporous structure according to claim 1, wherein the step (2) is specifically operated as follows: placing sodium hypophosphite in a quartz boat in the central heating zone at the upstream of the two-temperature zone tube furnace, and placing WO₃Putting white solid powder of the amine substance hybrid precursor on another quartz boat positioned in a central heating zone at the downstream of the double-temperature zone tubular furnace; introducing argon to remove air, and heating the downstream central heating zone to 3 ℃ at the temperature rise rate of 1-5 ℃/min under atmospheric pressurePreserving heat for 0.5-1.5h at 00-600 ℃, then heating to 650 plus materials at 850 ℃ at the heating rate of 1-10 ℃/min and preserving heat for 1-3h, simultaneously heating the upstream central heating zone to 250 plus materials at 350 ℃ and preserving heat for 1-3 h.

7. The preparation method of the carbon-doped WP nanosheet electrocatalyst with the mesoporous structure as claimed in claim 6, wherein argon is introduced to remove air as follows: before the heating process, vacuumizing and ventilating the quartz tube for 2 times under Ar atmosphere to obtain inert atmosphere; and in the temperature rise process, the argon flow of the gas path system is set to be 100s.c.c.m, and in the heat preservation stage, the argon flow is switched to be 10 s.c.c.m.

8. A carbon-doped WP nanosheet electrocatalyst with a mesoporous structure, characterized by being prepared by the preparation method of any one of claims 1-7.

Technical Field

The invention belongs to the technical field of electrocatalysis and hydrogen evolution electrode materials, and particularly relates to a carbon-doped WP nanosheet electrocatalyst with a mesoporous structure, and a preparation method of the carbon-doped WP nanosheet electrocatalyst with the mesoporous structure.

Background

The method for preparing the renewable clean energy hydrogen by electrocatalytic decomposition of water is a promising method because of the advantages of simple process, low cost, environmental protection, no pollution and the like. At present, the research focus in the field of hydrogen production by water electrolysis is how to develop a stable and efficient non-noble metal catalyst which can replace noble metals such as Pt.

Among them, two-dimensional transition metal semiconductor materials have been widely studied due to their wide sources and excellent properties, but these two-dimensional layered materials exhibit limited intrinsic electrocatalytic activity due to poor electrical conductivity and slow charge transfer kinetics. There are many strategies available today to enhance the electrical conductivity of materials, such as synthesizing metallic strong semiconductor materials or using highly conductive matrix materials (e.g., carbon materials or noble metals) that can significantly enhance the electrical conductivity of materials to enhance the electrocatalytic hydrogen evolution performance. Carbon materials have been receiving attention in various fields (such as energy, device, and catalyst) because of their excellent conductivity and stability, and particularly, have been widely used in the electrocatalytic direction, such as graphene, amorphous carbon materials, carbon nanotubes, and the like.

Disclosure of Invention

The invention aims to provide a preparation method of a carbon-doped WP nanosheet electrocatalyst with a mesoporous structure, and solves the problem that the existing WP nanosheet is not excellent in conductivity and electrocatalytic hydrogen evolution performance.

The second purpose of the invention is to provide a carbon-doped WP nanosheet electrocatalyst with a mesoporous structure, which is prepared by the method.

The first purpose of the invention is realized by the following technical scheme:

a preparation method of a carbon-doped WP nanosheet electrocatalyst with a mesoporous structure comprises the following steps:

(1) preparation of the sheet WO₃·2H₂O powder: mixing Na₂WO₄·2H₂Adding the O solution into the HCl solution for reaction, centrifuging the obtained light yellow suspension after the reaction is finished, washing the light yellow suspension for a plurality of times by using deionized water, and finally drying the obtained light yellow substance by using a freeze dryer to obtain the lamella WO₃·2H₂O block powder;

(2)WO₃preparation of amine substance hybrid precursor powder: get WO₃·2H₂Adding the O block powder and the amine substance into a polytetrafluoroethylene reaction kettle, reacting for 24-72h at the temperature of 100-200 ℃ to obtain white precipitate, centrifugally cleaning the white precipitate for a plurality of times by using ethanol, and drying the white precipitate to obtain WO₃White solid powder of amine substance hybrid precursor;

(3) preparation of WP @ C: sodium hypophosphite is used as a phosphorus source, and a double-temperature-control vacuum atmosphere tube furnace is used for firstly leading WO₃Decomposition of white solid powder of amine substance hybrid precursor into WO_x@ C complex, then WO_xThe @ C complex is phosphitylated and reduced to a sheet-like WP @ C electrocatalytic material.

The invention adopts a solvothermal method, a thermal decomposition method and an in-situ phosphorization reduction method, and uses a WO 3/amine substance hybrid precursor to prepare the carbon-doped WP nanosheet with the mesoporous structure. .

The preparation method of the invention can be further improved as follows:

the concentration of the sodium tungstate solution in the step (1): 1-3mol/L, hydrochloric acid solution concentration: 2-5 mol/L.

WO in step (2)₃·2H₂Mass of O powder: 0.1-2g, volume of amine substance:4-80mL。

in the step (2), the amine substance is one of n-propylamine, n-butylamine and n-octylamine.

The mass of the sodium hypophosphite in the step (2) is 1-3 g.

The step (2) is specifically operated as follows: placing sodium hypophosphite in a quartz boat in the central heating zone at the upstream of the two-temperature zone tube furnace, and placing WO₃Putting white solid powder of the amine substance hybrid precursor on another quartz boat positioned in a central heating zone at the downstream of the double-temperature zone tubular furnace; introducing argon to remove air, heating the downstream central heating zone to 600 ℃ at the temperature rise rate of 1-5 ℃/min under atmospheric pressure for 0.5-1.5h, then heating to 850 ℃ at the temperature rise rate of 650-10 ℃/min for 1-3h, simultaneously heating the upstream central heating zone to 350 ℃ at the temperature of 250-5 ℃ and preserving heat for 1-3 h.

Further, the operation of introducing argon to remove air is as follows: before the heating process, vacuumizing and ventilating the quartz tube for 2 times under Ar atmosphere to obtain inert atmosphere; and in the temperature rise process, the argon flow of the gas path system is set to be 100s.c.c.m, and in the heat preservation stage, the argon flow is switched to be 10 s.c.c.m.

The second purpose of the invention is realized by the following technical scheme:

a carbon-doped WP nanosheet electrocatalyst with a mesoporous structure is prepared by the method.

Compared with the prior art, the invention has the following beneficial effects:

(1) the carbon-doped WP nanosheet electrocatalyst with the mesoporous structure is prepared by the preparation method, and the material has a large specific surface area and excellent electrocatalytic hydrogen evolution performance. The current density in the acid electrolyte was 10mA cm^-2The overpotential is 190mV, the Tafel slope is 108mV dec^-1。

(2) The preparation method is novel, low in cost and simple to operate, provides valuable insight for improving the conductivity and the specific surface area of the carbon material modified material by using the carbon material so as to improve the performance, and contributes to promoting the development of the organic-inorganic hybrid catalyst material in the field of hydrogen evolution by electrocatalysis.

Drawings

Fig. 1 is an XRD spectrum of the WP @ C nanosheet electro-catalytic hydrogen evolution electrode material obtained in example 1 of the present invention.

Fig. 2 is an SEM image of the WP @ C nanosheet electrocatalytic hydrogen evolution electrode material obtained in example 1 of the present invention.

Fig. 3 and 4 are BET diagrams of the WP @ C nanosheet electrocatalytic hydrogen evolution electrode material obtained in example 1 of the present invention.

Fig. 5 is an LSV curve of the WP @ C nanosheet electrocatalytic hydrogen evolution electrode material obtained in example 1 of the present invention.

Fig. 6 is a Tafel plot of the WP @ C nanosheet electrocatalytic hydrogen evolution electrode material obtained in example 1 of the present invention.

Detailed Description

The present invention is further described below in conjunction with specific examples to better understand and implement the technical solutions of the present invention for those skilled in the art.