阅读说明：本技术 一种Ag纳米粒子负载硫化镍纳米片薄膜结构材料及其制备方法和应用 (Ag nano particle loaded nickel sulfide nanosheet film structure material and preparation method and application thereof ) 是由 吴正翠 王相宇 高峰 于 2020-06-11 设计创作，主要内容包括：本发明公开了一种Ag纳米粒子负载硫化镍纳米片薄膜结构材料及其制备方法和应用；所述制备方法为：首先制备得到2D纳米薄片状的Ni<Sub>3</Sub>S<Sub>2</Sub>纳米片薄膜；进一步在室温条件下用乙二醇作还原剂、柠檬酸盐作配位剂,在Ni<Sub>3</Sub>S<Sub>2</Sub>纳米片薄膜上还原沉积Ag纳米粒子；Ag纳米粒子负载能够提高导电性,增大电化学活性面积,加快界面电荷转移速率,优化Ni<Sub>3</Sub>S<Sub>2</Sub>对含氧/氢中间体的吸附和解吸特性；所述Ag纳米粒子负载Ni<Sub>3</Sub>S<Sub>2</Sub>纳米片薄膜结构材料可作为析氧反应、析氢反应和全水分解反应的电催化剂,具有活性高、耐久性好以及制备工艺简单的优点,对研究全水分解电催化电极材料的实际应用非常具有价值。(The invention discloses an Ag nano particle loaded nickel sulfide nanosheet film structure material and a preparation method and application thereof; the preparation method comprises the following steps: first, 2D nano flaky Ni is prepared 3 S 2 A nanosheet film; further using ethylene glycol as a reducing agent and citrate as a complexing agent at room temperature, in Ni 3 S 2 Reducing and depositing Ag nano particles on the nano sheet film; ag nanoparticle loading can be improvedConductivity, increased electrochemical active area, increased interface charge transfer rate, optimized Ni 3 S 2 Adsorption and desorption characteristics for oxygen/hydrogen containing intermediates; the Ag nano particle is loaded with Ni 3 S 2 The nanosheet film structure material can be used as an electrocatalyst for oxygen evolution reaction, hydrogen evolution reaction and full-water decomposition reaction, has the advantages of high activity, good durability and simple preparation process, and has great value for researching the actual application of the full-water decomposition electrocatalytic electrode material.)

1. Ag nano particle loaded Ni₃S₂The preparation method of the nanosheet film structure material is characterized by comprising the following steps:

(1) preparation of Ni₃S₂A nanosheet film;

(2) mixing Ni₃S₂Placing the nanosheet film into a silver nitrate aqueous solution containing citrate, adding ethylene glycol, stirring and reacting at room temperature, washing and drying after the reaction is finished to obtain Ag nano particle loaded Ni₃S₂A nanosheet film structure material.

2. The production method according to claim 1, wherein in the step (1), the Ni is₃S₂The preparation method of the nanosheet film comprises the following steps: dissolving thiourea and citrate in a mixed solution of methanol and water, transferring the solution to a reaction kettle, obliquely placing foamed nickel in the solution, carrying out solvothermal reaction, cooling after the reaction is finished, washing and drying a product to obtain Ni₃S₂A nanosheet film.

3. The method according to claim 1, wherein in the step (2), the ratio of the amounts of the silver nitrate and the citrate is 0.05 to 0.2: 5; the stirring reaction time is 60-80 min.

4. The method according to claim 1, wherein in the step (2), the concentration of the silver nitrate aqueous solution is 0.003M; the volume ratio of the silver nitrate aqueous solution to the ethylene glycol is 3: 1.

5. The method according to claim 2, wherein in the step (1), the solvothermal reaction is carried out at 160 ℃ for 8 hours; the volume ratio of water to methanol was 4: 3.

6. The preparation method according to claim 2, wherein in the step (1), the ratio of the concentrations of the thiourea and the citrate in the mixed solvent of water and methanol is 0.043: 0.002, and the concentration of the thiourea in the mixed solvent of water and methanol was 0.043M.

7. The preparation method according to any one of claims 1 to 6, wherein the Ag nano-particles prepared by the method are loaded with Ni₃S₂A nanosheet film structure material.

8. Ag nanoparticle loaded with Ni according to claim 7₃S₂The application of the nanosheet film structure material as an Oxygen Evolution Reaction (OER) electrocatalyst.

9. Ag nanoparticle loaded with Ni according to claim 7₃S₂Application of a nanosheet film structure material as a Hydrogen Evolution Reaction (HER) electrocatalyst.

10. Ag nanoparticle loaded with Ni according to claim 7₃S₂The application of the nano-sheet film structure material as an all-water decomposition reaction electrocatalyst.

Technical Field

The invention belongs to the field of nano material preparation methods and electrocatalysis application, and particularly relates to an Ag nano particle loaded nickel sulfide nanosheet film structure material and a preparation method and application thereof.

Background

The increasing demand for energy and the environmental pollution associated with the use of traditional fossil energy sources has forced people to search for and utilize efficient, inexpensive and environmentally friendly sustainable alternative energy sources. Hydrogen is considered as a powerful candidate energy source to replace traditional fossil fuels because of environmental friendliness and high energy density, and electrocatalytic water decomposition into hydrogen and oxygen is a renewable energy technology with development prospect and competitiveness. To date, Pt-based materials have been considered the most efficient electrocatalysts for Hydrogen Evolution Reactions (HER), while Ir/Ru oxides have been widely used as baseline electrocatalysts for Oxygen Evolution Reactions (OER), but their high cost and scarcity have limited the widespread use of these precious metals. Therefore, it is imperative to develop a bifunctional electrocatalyst capable of efficiently and sustainably catalyzing HER and OER from materials rich in global resources.

Ni₃S₂The presence of a large number of consecutive Ni-Ni and Ni-S bonds in the structure of (A) can promote the production of OOH as an intermediate of OER and the conversion of adsorbed H into H₂Are considered promising catalysts. Unfortunately, Ni₃S₂The low conductivity of the solution itself and the instability caused by the strong corrosiveness of the alkaline solution prevent its further application in electrocatalytic water splitting.

Disclosure of Invention

In order to solve the above-mentioned technical problems,the invention provides a nickel sulfide nanosheet film structure material loaded by ultra-small Ag nanoparticles and a preparation method and application thereof. Synthesizing Ag nano particle loaded Ni on foam nickel substrate by two-step liquid phase method₃S₂A nanosheet film structure material. By introducing noble metal Ag to construct a heterogeneous nano structure, the method can promote the promotion of the electrocatalytic performance by increasing the electron distribution on an active site and a reconstructed interface. In addition, the electronic interaction between the metal and the metal sulfide may allow the transfer of electrons from the metal to the metal sulfide, which will facilitate the adsorption and activation of water and weaken S-H by changing the electron density distribution of the electrocatalyst_adsBonds, thereby optimizing the adsorption and desorption of H. The invention introduces the conductive metal Ag into Ni₃S₂The heterogeneous nano structure constructed in the catalyst can also greatly improve the conductivity of the catalyst and accelerate the charge transfer between interfaces.

The Ag nano particle provided by the invention is loaded with Ni₃S₂The nanosheet film structure material can be used as an efficient OER, HER and total-moisture decomposition electrocatalyst. Ni₃S₂The two-dimensional nano-sheet has a larger exposed surface, can provide a large amount of active sites beneficial to a catalytic process, and can effectively adjust Ni by introducing metal Ag nano-particles₃S₂The electronic structure increases the number of active sites, enhances the conductivity of the catalyst, accelerates the electron transfer rate, and realizes outstanding catalytic activity and stability.

The Ag nano particle loaded with Ni provided by the invention₃S₂The preparation method of the nanosheet film structure material comprises the following steps:

(1) preparation of Ni₃S₂A nanosheet film;

(2) mixing Ni₃S₂Placing the nanosheet film into a silver nitrate aqueous solution containing citrate, adding ethylene glycol, stirring and reacting at room temperature, washing and drying after the reaction is finished, thus obtaining the Ag nanoparticle-loaded Ni₃S₂A nanosheet film structure material.

In the step (1), the Ni₃S₂Nanosheet sheetThe preparation method of the membrane comprises the following steps:

dissolving thiourea and citrate in a mixed solvent of methanol and water, transferring the solution to a reaction kettle, obliquely placing foamed nickel in the solution, carrying out a solvothermal reaction, cooling after the reaction is finished, washing and drying a product to obtain Ni₃S₂A nanosheet film.

Further, in the step (1), the concentration ratio of the thiourea and the citrate in the mixed solvent of water and methanol is 0.043: 0.002, and the concentration of the thiourea in the mixed solvent of water and methanol was 0.043M.

In the step (1), the volume ratio of the water to the methanol is 4: 3.

In the step (1), the solvothermal reaction condition is that the reaction is carried out for 8 hours at 160 ℃.

In the step (1), the foamed Nickel (NF) needs to be cleaned before use, and the specific cleaning steps are as follows: soaking in 6M hydrochloric acid for 15min to remove the outer oxide film, washing with deionized water and anhydrous ethanol for 3 times respectively, and naturally drying; when in use, the foam nickel is cut into the size of 2 multiplied by 3 cm.

The washing in the step (1) is 3 times of washing with deionized water and absolute ethyl alcohol respectively.

In the step (1), the drying is carried out in an oven at 60 ℃ for 8 h.

Further, the step (2) is specifically as follows: covering Ni obtained in the step (1)₃S₂Obliquely placing the foamed nickel of the nanosheet film in a silver nitrate aqueous solution containing citrate, finally adding ethylene glycol, reacting for 60-80 min at room temperature, respectively washing for 3 times by using deionized water and absolute ethyl alcohol, and drying in an oven at 60 ℃ for 8h to obtain Ag nano particle loaded Ni₃S₂A nanosheet film structure material.

Further, in the step (2), the concentration of the silver nitrate aqueous solution is 0.003M, the amount ratio of the silver nitrate to the citrate is 0.05-0.2: 5, and the volume ratio of the silver nitrate aqueous solution to the glycol is 3: 1.

Further, the room-temperature stirring reaction conditions are specifically as follows: reacting for 60min at 20-25 ℃.

In the steps (1) and (2), the citrate is trisodium citrate.

The invention provides Ag nano particle loaded Ni prepared by the preparation method₃S₂Nanosheet film structure material, Ni₃S₂Ag nano particles with the size of 2-3 nm are uniformly distributed on the nanosheet film.

The invention also provides Ag nano particle loaded Ni₃S₂The nano-sheet film structure material is applied as an electrocatalyst for oxygen evolution reaction, hydrogen evolution reaction or total water decomposition reaction.

The Ag nano particle is loaded with Ni₃S₂When the nanosheet film structure material is applied as an Oxygen Evolution Reaction (OER) electrocatalyst, the specific method comprises the following steps: ni-loaded Ag nanoparticles prepared on foamed nickel₃S₂Cutting a nanosheet film structure material into pieces with the size of 1 × 1cm to be used as a working electrode, taking 1M KOH as electrolyte, using a CHI760E electrochemical workstation to perform testing, using a platinum wire and an Ag/AgCl electrode as a counter electrode and a reference electrode respectively, and adopting a Linear Sweep Voltammetry (LSV) method to measure the voltage at 5.0 mV.s^-1The polarization curve is obtained at a scanning rate of 90% with ohmic compensation; stability was obtained by measuring the current density time curve at constant voltage. Electrochemically active area (ECSA) was determined by scanning (2, 4, 6, 8, 10, 12, 14 and 16mV · s) at different scan rates without significant faraday region^-1) Measuring the electric double layer capacitance (C) of a capacitor_dl) Carrying out evaluation; electrochemical Impedance (EIS) was tested at open circuit voltage in the frequency range of 100kHz to 0.1 Hz. Respectively with commercial RuO₂Ni supported on foamed nickel and prepared on foamed nickel₃S₂The nanosheet films were used as working electrodes and their OER properties were measured separately for comparison.

The Ag nano particle is loaded with Ni₃S₂When the nanosheet film structure material is applied as a Hydrogen Evolution Reaction (HER) electrocatalyst, the specific method comprises the following steps: ni-loaded Ag nanoparticles prepared on foamed nickel₃S₂Cutting the nano-sheet film structure material into 1 × 1cm as a working electrode, using 1M KOH as electrolyte, testing by using CHI760E electrochemical workstation, separating by using a carbon rod and an Ag/AgCl electrodeRespectively as a counter electrode and a reference electrode. Linear Sweep Voltammetry (LSV) at 5.0mV · s^-1The polarization curve is obtained at a scanning rate of 90% with ohmic compensation; stability was obtained by measuring the current density time curve at constant voltage. Ni prepared separately with commercial Pt/C loading on and on nickel foam₃S₂The nanosheet films were used as working electrodes and their HER performance was measured separately for comparison.

The Ag nano particle is loaded with Ni₃S₂When the nano-sheet film structure material is used as an all-water decomposition reaction electrocatalyst, the specific method comprises the following steps: ni-loaded Ag nanoparticles prepared on foamed nickel₃S₂2 nano-sheet film structural materials are cut into pieces with the size of 1 × 1cm and are respectively used as a cathode and an anode to be assembled in a double-electrode electrolytic tank, and the full-water decomposition performance is tested by a 90% iR compensated LSV polarization curve and a current density time curve under constant voltage₂Full water decomposition LSV polarization curves for anode and Pt/C cathode.

In the present invention, in Ni₃S₂The nanometer sheet is loaded with 2-3 nm of uniformly distributed ultra-small Ag nanometer particles, so that the electron distribution on the interface can be adjusted. Make Ag positively charged and can capture H₂O atom of O to adsorb activated H₂O molecule, which is favorable for the H-OH fragmentation. At the same time, Ni₃S₂The electron density of S is reduced, and S-H can be weakened_adsBonds, thereby optimizing the adsorption and desorption of H. Simultaneously Ag nano particles load Ni₃S₂The nano sheet can reduce the resistance, accelerate the charge transfer rate between the electrolyte and the catalyst and increase the electrochemical active area. Furthermore, Ni₃S₂The abundant Ni-S and Ni-Ni bonds can promote the generation of an OER intermediate OOH and the conversion of adsorbed H into H₂. Therefore, the material shows excellent activity and durability to oxygen evolution reaction, hydrogen evolution reaction and total hydrolysis reaction in alkaline electrolyte, and has great value for researching the practical application of the total hydrolysis electrocatalytic electrode material.

Compared with the prior artCompared with the prior art, the invention adopts a simple room temperature liquid phase deposition method to deposit Ni₃S₂Depositing Ag nano particles on the surface of the nano sheet film to obtain Ag nano particle loaded Ni₃S₂A nanosheet film. Ni₃S₂When the nano-sheet film is prepared, sulfur ions released by thiourea in the reaction solution react with Ni exposed on the surface of the foamed nickel to generate Ni₃S₂Crystal nucleus with citrate ion in Ni₃S₂Coordination on the crystal nucleus limits the growth of the crystal nucleus in the thickness direction, so that the crystal nucleus grows into 2D Ni₃S₂And (4) nano flakes. Ni loaded in preparation of Ag nano particles₃S₂When the nano-sheet film structure material is prepared, Ag is converted by glycol in the reaction solution⁺Reducing ions into zero-valent Ag to form Ag nano seeds, regulating the nucleation and growth rate of the Ag nano seeds by using a complexing agent citrate ions, and finally forming ultra-small Ag nano particles with the size of 2-3 nm and uniformly distributed in Ni₃S₂And (4) nano-chips.

The Ag nano particle provided by the invention is loaded with Ni₃S₂The nanosheet film structure material has excellent catalytic activity and stability for oxygen evolution reaction, hydrogen evolution reaction and full-water decomposition reaction in alkaline electrolyte, and has simple preparation process, environmental friendliness and great value for the practical application of full-water decomposition electrocatalyst materials.

Drawings

FIG. 1 shows that Ag nanoparticles prepared in example 1 are loaded with Ni₃S₂An X-ray powder diffraction (XRD) pattern of the nanosheet thin film structure material;

FIG. 2 shows that Ag nanoparticles prepared in example 1 are loaded with Ni₃S₂An energy dispersive X-ray spectroscopy (EDX) map of the nanosheet thin film structural material;

FIG. 3 shows that Ag nanoparticles prepared in example 1 are loaded with Ni₃S₂A Scanning Electron Microscope (SEM) image of the nanosheet thin film structure material;

FIG. 4 shows that Ag nanoparticles prepared in example 1 are loaded with Ni₃S₂A Transmission Electron Microscope (TEM) image of the nanosheet thin film structure material;

FIG. 5 shows that Ag nanoparticles prepared in example 1 are loaded with Ni₃S₂A High Resolution Transmission Electron Microscope (HRTEM) image of the nanosheet thin film structure material;

FIG. 6 shows that Ag nanoparticles prepared in example 1 are loaded with Ni₃S₂Scanning electron microscope images and corresponding element distribution images of the nano-sheet film structure material;

FIG. 7 shows that Ag nanoparticles with Ag loadings of 2.8% and 11.1% prepared in example 2 are loaded with Ni₃S₂An energy dispersive X-ray spectroscopy (EDX) map of the nanosheet thin film structural material;

FIG. 8 shows that Ag nanoparticles with Ag loading of 2.8% prepared in example 2 are loaded with Ni₃S₂A Scanning Electron Microscope (SEM) image of the nanosheet thin film structure material;

FIG. 9 shows that Ag nanoparticles with Ag loading of 11.1% prepared in example 2 are loaded with Ni₃S₂A Scanning Electron Microscope (SEM) image of the nanosheet thin film structure material;

FIG. 10 shows that Ag nanoparticles with Ag loading of 2.8% loaded in example 2 are loaded with Ni₃S₂A Transmission Electron Microscope (TEM) image of the nanosheet thin film structure material;

FIG. 11 shows that Ag nanoparticles with Ag loading of 11.1% and Ni were prepared in example 2₃S₂A Transmission Electron Microscope (TEM) image of the nanosheet thin film structure material;

FIG. 12 shows that Ag nanoparticles with different Ag contents (2.8%, 5.1% and 11.1%) prepared in examples 1 and 2 are loaded with Ni₃S₂An LSV curve graph of Oxygen Evolution Reaction (OER) of the nanosheet film structure material;

FIG. 13 shows that Ag nanoparticles are loaded with Ni in example 3₃S₂Nanosheet thin film structure material, Ni₃S₂Nanosheet film, RuO₂LSV profile of Oxygen Evolution Reaction (OER) with nickel foam;

FIG. 14 shows that Ag nanoparticles are loaded with Ni in example 3₃S₂A current density time curve graph of the Oxygen Evolution Reaction (OER) of the nanosheet film structure material;

FIG. 15 shows Ag nanoparticle loading in example 3Ni₃S₂Nanosheet thin film structure material and Ni₃S₂A capacitance-current diagram of the nano-sheet film under different scanning speeds;

FIG. 16 shows that Ag nanoparticles are loaded with Ni in example 3₃S₂Nanosheet film and Ni₃S₂An impedance plot of the nanosheet film;

FIG. 17 shows that Ag nanoparticles with different Ag contents (2.8%, 5.1% and 11.1%) prepared in examples 1 and 2 are loaded with Ni₃S₂An LSV curve chart of Hydrogen Evolution Reaction (HER) of the nanosheet film structure material;

FIG. 18 shows that Ag nanoparticles are loaded with Ni in example 4₃S₂Nanosheet thin film structure material, Ni₃S₂LSV curve graphs of nano-sheet film, Pt/C and foam nickel Hydrogen Evolution Reaction (HER);

FIG. 19 shows that Ag nanoparticles are loaded with Ni in example 4₃S₂A current density time curve diagram of Hydrogen Evolution Reaction (HER) of the nanosheet film structure material;

FIG. 20 shows that Ag nanoparticles are loaded with Ni in example 5₃S₂A polarization curve diagram of the total water decomposition of the nano-sheet film structure material in a two-electrode system;

FIG. 21 shows that Ag nanoparticles are loaded with Ni in example 5₃S₂And (3) a current density time curve diagram of the total-moisture decomposition of the nanosheet film structure material in a two-electrode system.

Detailed Description

The invention is described in detail below with reference to the following examples and the accompanying drawings.