阅读说明：本技术 一种电催化剂D-Mo2TiC2/Ni纳米片及其制备方法和应用 (Electrocatalyst D-Mo2TiC2/Ni nanosheet and preparation method and application thereof ) 是由 朱艳芳 于 2021-07-23 设计创作，主要内容包括：本发明公开了一种电催化剂D-Mo-(2)TiC-(2)/Ni纳米片及其制备方法和应用,制备方法包含：(1)将Mo-(2)TiAlC-(2)采用化学蚀刻得到Mo-(2)TiC-(2)纳米片；(2)将Mo-(2)TiC-(2)纳米片包覆的碳纸作为工作电极,石墨棒用作对电极,饱和甘汞电极用作参比电极,重复阴极极化循环以获得D-Mo-(2)TiC-(2)；(3)将D-Mo-(2)TiC-(2)分散在去离子水中形成悬浮液；(4)将Ni～(2+)水溶液加入到悬浮液中,固液分离,固体为Ni～(2+)/D-Mo-(2)TiC-(2)；(5)将Ni～(2+)/D-Mo-(2)TiC-(2)与尿素混合,在惰性气体环境中800℃退火,得到电催化剂。本发明的电催化剂能够用于催化析氢反应,具有较强的催化活性和稳定性。(The invention discloses an electrocatalyst D-Mo 2 TiC 2 The preparation method comprises the following steps: (1) mo is mixed with 2 TiAlC 2 Mo obtained by chemical etching 2 TiC 2 Nanosheets; (2) mo is mixed with 2 TiC 2 The carbon paper coated by the nano-sheets is used as a working electrode, the graphite rod is used as a counter electrode, the saturated calomel electrode is used as a reference electrode, and the cathodic polarization cycle is repeated to obtain D-Mo 2 TiC 2 (ii) a (3) Mixing D-Mo 2 TiC 2 Dispersing in deionized water to form a suspension; (4) mixing Ni 2+ Adding the aqueous solution into the suspension, and performing solid-liquid separation to obtain Ni as solid 2+ /D‑Mo 2 TiC 2 (ii) a (5) Mixing Ni 2+ /D‑Mo 2 TiC 2 Mixing with urea under inert conditionsAnnealing at 800 ℃ in a gas environment to obtain the electrocatalyst. The electrocatalyst can be used for catalyzing hydrogen evolution reaction and has stronger catalytic activity and stability.)

1. Electrocatalyst D-Mo₂TiC₂A method for producing a Ni nanosheet, characterized in thatThe preparation method comprises the following steps:

(1) mo is mixed with₂TiAlC₂Chemical etching is carried out in an autoclave at the temperature of 60-80 ℃ by adopting HCl solution containing LiF to obtain Mo₂TiC₂Nanosheets;

(2) mixing the Mo₂TiC₂The carbon paper coated by the nano-sheets is used as a working electrode, the graphite rod is used as a counter electrode, the saturated calomel electrode is used as a reference electrode, and the carbon paper is arranged in a three-electrode system at H₂SO₄Repeating the cathodic polarization cycle in the solution, keeping the scanning speed between 0 and 0.53V at 20mV/s, and applying 200 cycles to obtain the defect Mo₂TiC₂Nanosheet, denoted D-Mo₂TiC₂；

(3) Subjecting the D-Mo to₂TiC₂Dispersing in deionized water to form D-Mo₂TiC₂A suspension;

(4) mixing Ni²⁺Adding an aqueous solution to the D-Mo₂TiC₂In the suspension, after the reaction is finished, the solid-liquid separation is carried out to obtain the solid Ni²⁺/D-Mo₂TiC₂；

(5) Adding the Ni²⁺/D-Mo₂TiC₂Mixing the obtained product with urea according to the mass ratio of 1: 10-15, and annealing at 800 ℃ in an inert gas environment to obtain the electrocatalyst D-Mo₂TiC₂/Ni。

2. Electrocatalyst D-Mo according to claim 1₂TiC₂The preparation method of the/Ni nanosheet is characterized in that in the step (1), the HCl solution containing LiF is prepared from HCl aqueous solution with the molar concentration of 9mol/L and LiF, and the dosage of the LiF and the HCl aqueous solution is 1 g: 10 mL.

3. Electrocatalyst D-Mo according to claim 1₂TiC₂The preparation method of the/Ni nanosheet is characterized in that in step (1), chemical etching is carried out in an autoclave at 60 ℃ for 10 days.

4. Electrocatalyst D-Mo according to claim 1₂TiC₂The preparation method of the/Ni nano sheet is characterized in that in the step (1), Mo is adopted₂TiAlC₂The preparation method comprises the following steps:

mixing and grinding Mo, Ti, Al and C, sealing the mixture in an inert gas environment, heating at 1600 ℃, annealing after the reaction is finished, and grinding to obtain Mo₂TiAlC₂；

Wherein the mol ratio of Mo, Ti, Al and C is 0.2: 0.1: 0.11: 0.2.

5. electrocatalyst D-Mo according to claim 4₂TiC₂The preparation method of the/Ni nanosheet is characterized in that the heating time is 4 h.

6. Electrocatalyst D-Mo according to claim 1₂TiC₂The preparation method of the/Ni nano sheet is characterized in that in the step (2), the H₂SO₄Solution of 0.1mol/L of H₂SO₄An aqueous solution.

7. Electrocatalyst D-Mo according to claim 1₂TiC₂The preparation method of the/Ni nanosheet is characterized in that in the step (4), Ni with the molar concentration of 3mg/mL is added under stirring²⁺Adding an aqueous solution to the D-Mo₂TiC₂Stirring the suspension for 24 hours; the D-Mo₂TiC₂And Ni²⁺The amount of aqueous solution used was 0.1 g: 40 mL.

8. Electrocatalyst according to any one of claims 1-7, D-Mo₂TiC₂The preparation method of the/Ni nanosheet is characterized in that in the step (5), the annealing time is 1 h.

9. Electrocatalyst D-Mo prepared according to the process of any one of claims 1-8₂TiC₂a/Ni nano sheet.

10. As claimed in claim 9The electrocatalyst D-Mo₂TiC₂Application of the/Ni nanosheet in catalyzing hydrogen evolution reaction.

Technical Field

The invention relates to an electrocatalyst, in particular to an electrocatalyst D-Mo₂TiC₂A Ni nano sheet and a preparation method and application thereof.

Background

The widespread use of fossil fuels has been a history of over two hundred years, which has led to serious energy crisis and global warming for the last several decades, and the search for sustainable, clean alternative fuels for human survival has become increasingly urgent. The energy density of hydrogen is as high as 140MJ/kg, only water is generated after combustion, and the hydrogen is considered as the most promising clean energy. Typical current methods for producing hydrogen are to convert natural gas or coal to steam, but still rely heavily on fossil fuels. Methods for sustainable hydrogen production are still under development, such as Hydrogen Evolution Reaction (HER) of cracked water. The electrochemical hydrogen evolution technology of electrocatalytic water cracking has attracted people's attention. The Pt-based electrocatalyst is effective in reducing HER overpotential. However, the high price and scarcity of platinum greatly limit its implementation in practical applications. Therefore, the search for efficient and economical hydrogen evolution electrocatalysts has become the focus of much pioneering work.

Disclosure of Invention

The invention aims to provide an electrocatalyst D-Mo₂TiC₂The electrocatalyst can be used for catalyzing hydrogen evolution reaction, has stronger catalytic activity and stability, lower HER overpotential, excellent HER dynamics, larger effective surface area and lower charge transfer resistance.

In order to achieve the above object, the present invention provides an electrocatalyst D-Mo₂TiC₂The preparation method of the/Ni nano sheet comprises the following steps:

(1) mo is mixed with₂TiAlC₂Chemical etching is carried out in an autoclave at the temperature of 60-80 ℃ by adopting HCl solution containing LiF to obtain Mo₂TiC₂Nanosheets; the influence of temperature on the characteristics of the etching solution is large, the temperature plays an important role in accelerating the fluidity of the solution, reducing the viscosity of the etching solution and improving the etching rate, but the temperature is too high, chemical components are easy to volatilize, chemical proportion is disordered, a high polymer resist layer is damaged, the service life of equipment is influenced, and therefore the temperature is controlled to be 60-80 ℃;

(2) mixing the Mo₂TiC₂The carbon paper coated by the nano-sheets is used as a working electrode, the graphite rod is used as a counter electrode, the saturated calomel electrode is used as a reference electrode, and the carbon paper is arranged in a three-electrode system at H₂SO₄Repeating the cathodic polarization cycle in the solution, keeping the scanning speed between 0 and 0.53V at 20mV/s, and applying 200 cycles to obtain the defect Mo₂TiC₂The nano-sheet is prepared by the steps of,is marked as D-Mo₂TiC₂；

(3) Subjecting the D-Mo to₂TiC₂Dispersing in deionized water to form D-Mo₂TiC₂A suspension;

(4) mixing Ni²⁺Adding an aqueous solution to the D-Mo₂TiC₂In the suspension, after the reaction is finished, the solid-liquid separation is carried out to obtain the solid Ni²⁺/D-Mo₂TiC₂；

(5) Adding the Ni²⁺/D-Mo₂TiC₂Mixing the obtained product with urea according to the mass ratio of 1: 10-15, and annealing at 800 ℃ in an inert gas environment to obtain the electrocatalyst D-Mo₂TiC₂/Ni。

Preferably, in the step (1), the HCl solution containing LiF is prepared by using an aqueous HCl solution with a molar concentration of 9mol/L and LiF, and the amounts of the LiF and the aqueous HCl solution are 1 g: 10 mL.

Preferably, in step (1), the chemical etching is performed in an autoclave at 60 ℃ for 10 days.

Preferably, in step (1), the Mo is₂TiAlC₂The preparation method comprises the following steps: mixing and grinding Mo, Ti, Al and C, sealing the mixture in an inert gas environment, heating at 1600 ℃, annealing after the reaction is finished, and grinding to obtain Mo₂TiAlC₂(ii) a Wherein the mol ratio of Mo, Ti, Al and C is 0.2: 0.1: 0.11: 0.2.

preferably, the grinding time is 30 min.

Preferably, the heating time is 4 h.

Preferably, in step (2), said H₂SO₄Solution of 0.1mol/L of H₂SO₄An aqueous solution.

Preferably, in step (4), Ni is added at a molar concentration of 3mg/mL with stirring²⁺Adding an aqueous solution to the D-Mo₂TiC₂Stirring the suspension for 24 hours; the D-Mo₂TiC₂And Ni²⁺The amount of aqueous solution used was 0.1 g: 40 mL.

Preferably, in step (5), the annealing time is 1 h.

Another object of the present invention is to provide an electrocatalyst D-Mo prepared by said method₂TiC₂a/Ni nano sheet.

Another object of the present invention is to provide the electrocatalyst D-Mo₂TiC₂Application of the/Ni nanosheet in catalyzing hydrogen evolution reaction.

Electrocatalyst D-Mo of the invention₂TiC₂The Ni nano-sheet, the preparation method and the application thereof have the following advantages:

electrocatalyst D-Mo of the invention₂TiC₂the/Ni nanosheet can be used for catalyzing hydrogen evolution reaction, and the catalyst has strong catalytic activity and stability. And Mo₂TiC₂Nanosheet, D-Mo₂TiC₂In contrast, the D-Mo of the invention₂TiC₂the/Ni catalyst has lower HER overpotential, excellent HER dynamics, larger effective surface area and lower charge transfer resistance.

Electrocatalyst D-Mo of the invention₂TiC₂Ni nanosheet using Mo₂TiC₂The Mo vacancy of the nanoplatelets serves as an active site to anchor the Ni single atom to improve HER activity. Electrocatalyst D-Mo of the invention₂TiC₂The catalytic efficiency of the/Ni nanoplates can persist for 10,000 cycles.

Drawings

FIG. 1 shows Mo prepared in example 1 of the present invention₂TiC₂And D-Mo₂TiC₂A structural representation of (a); a is Mo₂TiC₂SEM picture of (1); b is Mo₂TiC₂HRTEM (in-plane) of; c is Mo₂TiC₂HRTEM (out of plane) of; d is D-Mo₂TiC₂SEM picture of (1); e is D-Mo₂TiC₂(ii) a Raman spectrogram; f is D-Mo₂TiC₂HRTEM of (g).

FIG. 2 shows a catalyst D-Mo prepared in example 1 of the present invention₂TiC₂Structural representation of/Ni.

FIG. 3 shows Mo prepared in example 1 of the present invention₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂X-ray diffraction pattern of/Ni.

FIG. 4 shows D-Mo prepared in example 1 of the present invention₂TiC₂Catalyst D-Mo₂TiC₂X-ray photoelectron spectroscopy (XPS) of/Ni.

FIG. 5 is an x-ray absorption study; a is D-Mo₂TiC₂XANES spectra of/Ni, nickel foil and NiO; b is D-Mo₂TiC₂Fourier transform of EXAFS spectra of Ni K-edge for/Ni, Ni foil and NiO.

FIG. 6 shows Mo prepared in example 1 of the present invention₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂Electrochemical performance results for/Ni and Pt/C.

FIG. 7 shows Mo prepared in example 1 of the present invention₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂Comparison of/Ni and Pt/C; a and b are Mo₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂Tafel plots and Tafel slides for/Ni and Pt/C; c is Mo₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂Capacitance of/Ni and Pt/C at different scan rates; d is Mo₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂Nyquist plots for/Ni and Pt/C.

FIG. 8 is a graph of D-Mo prepared by evaluation after cycling of electrochemical reactions₂TiC₂Stability results for the/Ni catalyst.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Electrocatalyst D-Mo₂TiC₂A method of preparing Ni nanoplates, the method comprising:

(1) defective Mo₂TiC₂Synthesis of nanosheets:

Mo₂TiAlC₂mo (0.2mol), Ti (0.1mol), Al (0.11mol) and C (graphite, 0.2mol) were mixed in a glove box and ground inside for 30 min. The mixture was then sealed in a quartz tube in an Ar atmosphere and heated in a tube furnace at 1600 ℃ for 4 h. Thereafter, the annealed product was ground with a mortar/pestle to obtain Mo₂TiAlC₂。

Mo₂TiC₂Nanosheet Mo by chemical etching₂TiAlC₂The synthesis method specifically comprises the following steps:

mo is stirred under magnetic force₂TiAlC₂The powder (0.5g) was added to a HCl solution (50mL, 9mol/L) containing LiF (5 g). The suspension was transferred to an autoclave with mechanical means (one atmosphere) and stirred for 10 days at 60 ℃. Finally, washing the product with deionized water for 5 times to obtain Mo₂TiC₂Nanosheets.

Defective Mo₂TiC₂Defects on the nanoplatelets are created by introducing Mo vacancies, which can serve as anchor sites for a single Ni atom, which are created by the Electrochemical Exfoliation Process (EEP) in a three-electrode system, as follows:

using Mo₂TiC₂The carbon paper coated by the nanosheets is used as a working electrode, the graphite rod is used as a counter electrode, and the Saturated Calomel Electrode (SCE) is used as a reference electrode. Electrochemical stripping process by₂SO₄Repeated cathodic polarization cycles in (0.1mol/L) solution, scan rate maintained at 20mV/s between 0-0.53V (vs. RHE), and 200 cycles applied to obtain defective Mo₂TiC₂Nanosheet (D-Mo)₂TiC₂)。

(3) Catalyst D-Mo₂TiC₂Preparation of/Ni

Using Ni (NO)₃)₂·6H₂O (30mg) preparation of 100mLNi²⁺Aqueous solution (3 mg/mL).

Carrying out ultrasonic treatment for 30min and mechanical stirring for 30min to remove Mo in the defect₂TiC₂The nanoplatelets (0.1g) were dispersed in 20mL of deionized water. The Ni is stirred vigorously²⁺Aqueous solution (40mL) was added to the defective Mo₂TiC₂Nanosheet suspension for 24 h. Thereafter, the particles are separated from the liquid by a centrifuge. Ni²⁺/D-Mo₂TiC₂Mixing the powder and urea according to the mass ratio of 1:10, annealing for 1h at 800 ℃ in an Ar gas environment to finally obtain the catalyst D-Mo₂TiC₂/Ni。

As shown in FIG. 1, the synthesized Mo was examined for completeness and defects under an electron microscope₂TiC₂Microstructure of the sample. Complete Mo₂TiC₂The sample consists of randomly arranged nanoplatelets as shown in a of figure 1. The in-plane HRTEM image in b of fig. 1 shows a distance between two atomic layers of 1.02 nm. Furthermore, the out-of-plane HRTEM image in c of fig. 1 shows a regular array of atoms (d ═ 0.34nm), indicating that the prepared sample has good crystallinity. After creating Mo vacancies, Mo complete with in a of FIG. 1₂TiC₂Nanosheet-in contrast, Mo, defective in d of FIG. 1₂TiC₂The nanoplatelets remain unchanged in morphology. After a careful review of the array of atoms shown in e of fig. 1, a number of defects were observed due to the absence of Mo atoms. Furthermore, as shown by the Raman spectrum in f of FIG. 1, with intact Mo₂TiC₂Comparison of samples, defective Mo₂TiC₂The D and G bands of (2) are better split, indicating defective Mo₂TiC₂There is a more pronounced atomic disorder.

As shown in FIG. 2, the catalyst D-Mo prepared in inventive example 1₂TiC₂Structural representation of/Ni, a: SEM picture; b: a TEM image; c: HRTEM image; d: a STEM graph; e: a Ti element distribution diagram; f: distribution diagram of Ni element. It can be seen that Mo is introduced into the alloy after Ni monoatomic ions are introduced₂TiC₂The overall morphology of the nanoplatelets remains unchanged. D-Mo in b of FIG. 1₂TiC₂TEM image of/Ni shows that there are some lighter sites and some darker sites in the lattice compared to the original atomic sites, which are divided intoCorresponding to loading Ni atoms and Mo vacancies, respectively. In fig. 1 c, the magnified image obtained under HRTEM confirms that some Mo vacancies are occupied by Ni monoatomic atoms, while other Mo vacancies remain unoccupied. Ni atoms tend to occupy Mo vacancies because the defect sites are unstable and are more energetic and more susceptible to chemical reactions. Based on the STEM image in d of fig. 1, the distribution of Ti and Ni was investigated. As shown in e and f of fig. 1, Ti and Ni are uniformly distributed in the sample. The signal of Ti is stronger than that of Ni because Ti is a component of the host material, and Ni is supported in a small amount as a single atom.

As shown in FIG. 3, Mo prepared for inventive example 1₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂X-ray diffraction (XRD) pattern of/Ni, and the crystallinity of the synthesized sample is researched through XRD pattern, and the complete Mo₂TiC₂The diffraction peaks of the sample are (002), (004), (006), (0010), (0012) and (0014).

As shown in FIG. 4, D-Mo prepared for inventive example 1₂TiC₂Catalyst D-Mo₂TiC₂X-ray photoelectron spectroscopy (XPS) pattern of/Ni, a: mo 3 d; b: ti 2 p; c: c1 s; d: ni 2p, the chemical state of the element was studied by X-ray photoelectron spectroscopy. As shown in a of FIG. 4, in D-Mo₂TiC₂In the sample, XPS peaks at 228eV and 231eV are respectively attributed to 3d of Mo bonded to C_5/2And 3d_3/2. After the introduction of Ni monoatomic, both peaks showed a slight shift, probably due to the low loading of Ni. Similarly, D-Mo₂TiC₂Ti in the sample showed two XPS peaks at 454.5eV and 461eV, respectively due to 2p_3/2And 2p_1/2. The incorporation of Ni leads to XPS peak of Ti towards D-Mo₂TiC₂The lower binding energy direction in the/Ni samples shifted very slightly. For the XPS peak of C in FIG. 4, the relative intensities of the two peaks change significantly after loading the Ni monoatomic atom, probably due to the change in the chemical environment of C. As previously mentioned, Ni monoatomic atoms are undetectable using XRD. Therefore, it is necessary to confirm the presence of Ni in the sample detected by XPS. As shown in d of FIG. 4, XPS spectra of Ni can be fit to fourAre respectively allocated to Ni⁰2p_3/2、Ni²⁺2p_3/2、Ni²⁺2p_3/2Satellite and Ni⁰2p_3/2The peak of the satellite. This indicates that Ni atoms have been successfully loaded into defective Mo by in situ reduction₂TiC₂In the sample.

Experimental example 1 electrochemical test

Electrochemical tests were carried out on an electrochemical workstation (CHI 600E, CH Instrument) with a three-electrode system (counter electrode: graphite rod; reference electrode: SCE, saturated calomel electrode; working electrode).

The working electrode was carbon paper with a coating of catalyst paste. Among them, the catalyst slurry was obtained by mixing a catalyst (2mg), Nafion (80 μ L, 6 wt%), and ethanol (1mL) and sonicating for 1 h. 0.25mL of the catalyst slurry was dropped onto carbon paper (0.7 cm. times.0.7 cm) at a catalyst loading of about 1mg/cm²And then the ethanol was evaporated in a vacuum chamber at room temperature. Pt/C (40%) catalyst powder is commercially available.

The polarization curve was obtained at a scan rate of 5mV/s and pH 2. In order to determine the electrochemical capacitance, CV measurements are performed at an open circuit potential with a scan rate of 10 to 1000 millivolts per second. The EIS spectrum is measured between 102Hz and 106 Hz. By repeated linear sweep voltammetry 10⁴The cycling stability was evaluated.

Evaluation of the prepared D-Mo after 10,000 cycles of electrochemical reaction₂TiC₂Stability of the/Ni catalyst. The results are shown in the TEM image in fig. 8 a, demonstrating a well-defined lattice (d ═ 0.34 nm). In b of FIG. 8, after 120h, D-Mo at-150 mV₂TiC₂The current density of the/Ni is reduced from-31.7 to 28.9mA/cm². Meanwhile, the current density of Pt/C at-50 mV is reduced by 7.10%. Indicating synthetic D-Mo₂TiC₂the/Ni catalyst is sufficiently stable to be used for a long period of time.

D-Mo of the invention₂TiC₂The catalytic efficiency of the/Ni catalyst can last for 10,000 cycles, indicating that D-Mo₂TiC₂the/Ni catalyst is durable.

As in fig. 5XANES spectra in a show Ni L₃The strength of the edge is NiO, DMo₂TiC₂The order of the/Ni and Ni foils decreases. This indicates that D-Mo₂TiC₂The valence of Ni in/Ni is between those of NiO and Ni foil. Ni carries a +2 charge in NiO and is neutral in Ni foil. D-Mo₂TiC₂The Ni center in the/Ni will be positively charged because electrons are transferred from Ni to Mo through Ni-Mo interactions. Furthermore, the Ni K-edge EXAFS spectra of Ni foil and NiO in b of FIG. 5 show that Ni-Ni interaction in the first shell of Ni foil isThe Ni-Ni interaction in the second shell of NiO isNi-O interaction of NiO toD-Mo₂TiC₂These characteristics are not observed with/Ni, which indicates that the Ni monoatomic atoms are highly dispersed and in D-Mo₂TiC₂No interaction in the/Ni catalyst.

As shown in FIG. 6, Mo prepared for inventive example 1₂TiC₂Nanosheet, D-Mo₂TiC₂Catalyst D-Mo₂TiC₂Electrochemical performance results of/Ni and Pt/C, a: a HER polarization curve; b: at 10mA/cm²Overpotential at current density. The electrocatalytic activity of the resulting samples was evaluated by measuring the overpotential, as shown in a of fig. 6. As its reference electrocatalyst, Pt/C generates 10mA/cm at the most active potential²Indicating that the overpotential is the lowest. In addition, according to D-M₂TiC₂/Ni，D-Mo₂TiC₂And Mo₂TiC₂In the order of (1), yield 10mA/cm²The potential for the current density of (a) to move from a more positive potential to a more negative indicates her excessive growth. The current density is 10mA/cm²Is extracted from a of fig. 6 and plotted in b of fig. 6. By Pt/C, D-Mo₂TiC₂/Ni，D-Mo₂TiC₂And Mo₂TiC₂In this order, the overpotential sharply increases. Shows that along with the introduction of MO vacancy and Ni single atom, the electrocatalytic activity of the catalyst is greatly improved.

As shown in FIG. 7, from a and b, it can be seen that the existing electrocatalyst PT/C exhibits a flat Tafel plot implying minimum slope, in terms of D-Mo₂TiC₂/Ni、D-Mo₂TiC₂And Mo₂TiC₂In this order, Tafel Plot becomes steep. When the electrocatalyst is PT/C, the Tafel slope is 32.6mV/dec, and the slope is minimum; secondly, the smaller Tafel slope is D-Mo₂TiC₂56.7mV/Dec when Ni is an electrocatalyst; then D-Mo₂TiC₂88.1mV/Dec in the case of electrocatalyst; finally Mo is₂TiC₂In the case of an electrocatalyst, the slope was 135mV/Dec, with the maximum slope. D-Mo₂Tic₂the/Ni showed the highest double layer capacitance in the studied catalyst, which is very close to the value of the reference catalyst Pt/C. Shows D-Mo₂TiC₂the/Ni has the largest effective surface area and the most active sites for redox reactions.

Mo of the invention₂TiC₂The Mo vacancy of the nanoplatelets serves as an active site to anchor the Ni single atom to improve HER activity. Comparative complete Mo₂TiC₂Catalyst and defect Mo without Ni load₂TiC₂D-Mo of the invention₂TiC₂/Ni exhibits lower HER, excellent HER kinetics, larger effective surface area and low charge transfer resistance over-current.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.