Method for surface reconstruction of ligand-regulated oxygen evolution catalyst, catalyst and application

Abstract

The invention discloses a method for surface reconstruction of a ligand-regulated oxygen evolution catalyst, the catalyst and application of the catalyst. The methods involve ligand tuned surface reconstruction capable of simultaneous incorporation of doped cations and oxygen vacancies to improve the catalytic activity of the OER. Surface engineered heterointerface structures consisting of nickel-based precatalysts and (oxy) hydroxides have been developed based on the ligand-induced delayed doping effect using ammonia complexes in alkaline electrolytes by using nickel telluride, nickel oxide, nickel sulfide or nickel selenide as the precatalyst. The method is simple in process, easy to operate and capable of being industrially popularized; and the prepared oxygen evolution catalyst has the characteristics of abundant active sites and oxygen vacancies, large chemical active surface area, good stability, controllability and low cost.

Description

Technical Field

[0001] The invention relates to a preparation method of an oxygen evolution catalyst, a catalyst and an application thereof, and in particular to a method for regulating the surface reconstruction of an oxygen evolution catalyst by a ligand, a catalyst and an application thereof. Background Art

[0002] Escalating energy demands and pressing global warming concerns have forced society to increasingly rely on renewable energy sources. Water electrolysis is considered a promising approach to convert electrical energy provided by renewable energy sources such as wind, solar, and tidal power into chemical energy through an electrocatalytic process for a variety of applications in the future hydrogen economy. The development of efficient and durable cathode hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) electrocatalysts is critical to unlocking the potential of water electrolysis. However, practical water-splitting electrolyzers face limitations such as low operating efficiency and high cell voltage, primarily attributed to the anode OER. OER(4OH - →O 2 +2H 2 O+4e - , vs. RHE) involves a multi-step proton-coupled electron transfer process whose sluggish reaction kinetics greatly hinder the overall efficiency of the reaction, emphasizing the necessity of addressing the challenge of developing efficient OER catalysts for widespread implementation of water electrolysis. According to the Sabatier principle, the binding strength of oxygen on the catalyst surface should not be too strong or too weak to achieve efficient catalytic purposes.

[0003] Currently, state-of-the-art OER catalysts, such as noble metal-based materials such as Ir, Ru and their corresponding alloys and oxides, face major limitations in large-scale applications due to their scarcity, high cost and stability issues. In view of this fact, it is of great significance and urgency to develop highly active, low-cost and efficient non-noble metal catalysts for OER with abundant reserves.

[0004] To date, various transition metal (TM) based materials, including metal alloys, hydroxides, oxides, sulfides, selenides, tellurides, borides, nitrides, carbides, phosphides, metal organic frameworks and their derivatives, have been widely studied for catalyzing OER in alkaline electrolytes, and significant progress has been achieved. OER catalysts can be divided into three types according to the degree of phase and structural changes in the high oxidation potential range. The first type of catalysts remain stable without oxidation and show intrinsic activity as OER catalysts in their original state even under alkaline oxidizing conditions. The second type involves complete oxidation under OER conditions, resulting in conversion to low crystalline or amorphous metal oxides / (oxy)hydroxides. In the third type, partial oxidation occurs, in which the catalyst surface is transformed into low crystalline or amorphous oxides / (oxy)hydroxides, while the material core remains in its unoxidized state, forming a core-shell catalyst.

[0005] Currently, transition metal (oxy)hydroxides are formed through irreversible structural transformation of precatalysts and are widely considered to be the main catalytic species for OER, which are more thermodynamically stable than precatalysts. The structural transformation can change the atomic arrangement and crystal structure on the catalyst surface, thereby changing the distribution of active sites and specific surface area. At the same time, it significantly affects the surface energy, adsorption and diffusion of reactants, and the stability of the catalyst. Some cationic species show high instability during the OER process, may leach from the lattice, and cause significant structural changes in the precatalyst.

[0006] However, the leaching mechanisms of metal impurities are often complex and intricately linked to composition, structure, and defects, making the reconstruction mechanism complicated and challenging. In addition, specific anions undergo oxidation and dissolution during the OER process, leading to the oxidation of transition metal sites and the formation of metal oxides / (oxy)hydroxides. During the structural reformation process, the leaching of cationic or anionic species can lead to the formation of low crystalline or amorphous phases with porous structures, increasing the specific surface area, exposing more loosely structured active sites, and ultimately improving the OER catalytic performance.

[0007] However, the above reconstruction types require precise synthesis of precatalysts, long activation periods, and often involve complex and elusive dissolution mechanisms, resulting in limited applicability of this strategy. In contrast, during the electrochemical activation process, the introduction of impurity metals or anionic groups into the electrolyte can promote cation doping or adsorption of anionic groups on the surface structure, thereby enhancing the catalytic activity of metal sites. This strategy has significant adaptability and feasibility. However, the metal ions in alkaline electrolytes react with OH groups to form catalytic sites. - The tendency to combine and form precipitates often limits the metal doping level (ppm level), thus hindering the potential enhancement of catalytic activity.

[0008] Therefore, exploring a faster, more efficient, and more scalable electrolyte regulation strategy is crucial for designing highly active OER catalysts and deepening the understanding of the OER catalytic mechanism. Summary of the invention

[0009] In order to solve the above technical problems, the present invention provides a method for ligand-regulated surface reconstruction of oxygen evolution catalysts, a catalyst and an application. The method involves ligand-tuned surface reconstruction, which can simultaneously incorporate doped cations and oxygen vacancies to improve the catalytic activity of OER. By using nickel-based materials as pre-catalysts, based on the ligand-induced delayed doping effect of ligand sources in alkaline electrolytes, a surface-engineered heterogeneous interface structure consisting of a nickel-based pre-catalyst and (oxy)hydroxides was developed. By comparing different ligands, such as neutral ligands (NH 3 , H 2O), anionic ligand (NCS -1 , CN -1 ), and found that the performance of the pre-catalyst after surface reconstruction is related to the strength of the coordination field of the ligand and the charge it carries. In the electrochemical activation process, the delayed doping effect produced has a significant promoting effect on metal ion doping and the generation of oxygen vacancies. The method of the present invention is simple in process, easy to operate, and can be promoted industrially; and the prepared oxygen evolution catalyst has the characteristics of abundant active sites and oxygen vacancies, large chemically active surface area, good stability, controllability, and low cost.

[0010] One of the technical solutions of the present invention:

[0011] A method for ligand-regulated surface reconstruction of an oxygen evolution catalyst is provided, comprising the following steps:

[0012] S1. Wash and dry the nickel foam for later use;

[0013] S2. Put Na 2 TeO 3 Dissolve in water, then add hydrazine hydrate and stir evenly to obtain liquid A;

[0014] S3. The nickel foam is placed in a reactor, and then the liquid A is transferred to the reactor, heated to react, and the reaction is naturally cooled to room temperature after completion;

[0015] S4. Take out the substrate of S3, rinse it with water and ethanol in turn, and then dry it to obtain the pre-catalyst NiTe x -original;

[0016] S5. Add ligand source, Fe(NO 3 ) 3 9H 2 O、Na 2 MoO 4 ·2H 2 O and Cr(NO 3 ) 3 9H 2 O, to obtain electrolyte;

[0017] S6. NiTe obtained in S4 x -original was placed in the electrolyte obtained from S5 for cyclic voltammetry activation, then rinsed with water and ethanol in turn, and finally dried to obtain a ligand-regulated oxygen evolution catalyst named: NiTe x / FeCrMo-ligand.

[0018] Preferably, in the aforementioned method for ligand-regulated surface reconstruction of oxygen evolution catalyst, the nickel foam in S1 is washed with acetone, ethanol, hydrochloric acid and water in sequence.

[0019] Preferably, in the aforementioned method for regulating the surface reconstruction of oxygen evolution catalyst by ligand, in said S2, Na 2 TeO 3 The molar concentration is 30-50 mmol / L, and the volume ratio of hydrazine hydrate to water is 0.5-1.5:10.

[0020] Preferably, in the aforementioned method of ligand-regulated surface reconstruction of oxygen evolution catalyst, the stirring time in S2 is 20-40 min.

[0021] Preferably, in the aforementioned method of ligand-regulated surface reconstruction of oxygen evolution catalyst, the heating temperature in S3 is 150-200° C., and the reaction time is 20-30 h.

[0022] Preferably, in the aforementioned method of ligand-regulated surface reconstruction of oxygen evolution catalyst, the drying temperature in S1, S4 and S6 is 50-70° C. and the drying time is 8-9 h.

[0023] Preferably, in the aforementioned method for regulating the surface reconstruction of oxygen evolution catalyst by ligand, the concentration of the KOH solution in S5 is 0.8-1.2 mol / L, the ligand source, Fe(NO 3 ) 3 9H 2 O、Na 2 MoO 4 ·2H 2 O and Cr(NO 3 ) 3 9H 2 The mass ratio of O is 1:1-2:1-2:1-2.

[0024] Preferably, in the aforementioned method for regulating the surface reconstruction of oxygen evolution catalyst by ligand, the ligand source in S5 is NH 4 F, KSCN or K 3 [Fe(CN) 6 ], preferably NH 4 F.

[0025] Preferably, the aforementioned method for regulating the surface reconstruction of the oxygen evolution catalyst by ligand, the cyclic voltammetry method in S6, is based on NiTe x -original was the working electrode, carbon rod was the counter electrode, and Hg / HgO was the reference electrode; the CV scanning voltage range was -0.1-1.0 V, the scanning rate was 50 mV / s, and the number of scanning cycles was 200 cycles.

[0026] Preferably, the above-mentioned method of regulating the surface reconstruction of the oxygen evolution catalyst by ligand can also be used to convert the pre-catalyst NiTe in S6 x -original replaced with NiO, NiS2 or NiSe 2 After the pre-catalyst is replaced, the steps S1-S4 can be omitted.

[0027] The second technical solution of the present invention:

[0028] Provided is a ligand-regulated oxygen evolution catalyst, which is prepared by the method of scheme one.

[0029] The third technical solution of the present invention:

[0030] Provided is an application of a ligand-regulated oxygen evolution catalyst in catalytic oxygen evolution reaction.

[0031] Beneficial effects of the present invention:

[0032] 1. The process of the present invention is simple, easy to operate, and convenient for industrial promotion and implementation.

[0033] 2. Material NiTe prepared by the present invention x / FeCrMo- ligands have abundant active sites and oxygen vacancies.

[0034] After electrochemical CV activation, such as NiTe x / FeCrMo-NH 4 F forms a truly active MOOH phase on the surface of the material, NH 4 F provides the ligand NH 3 , forming a complex with the metal element Fe, avoiding the formation of metal hydroxide precipitation, and the metal elements Fe and Cr in the electrolyte are doped into MOOH, while the doped metal element Mo does not enter the crystal lattice due to its large atomic radius, high valence state, and large migration barrier, but promotes the formation of oxygen vacancies in the catalyst, further improving the oxygen evolution catalytic activity (OER) of the catalyst.

[0035] 3. The method of the present invention is simpler than the traditional method. By controlling the concentration and position of doping, the concentration distribution and position distribution of doping atoms can be adjusted, thereby achieving flexible regulation of the active sites of the catalyst.

[0036] After doping and vacancy regulation, the reaction energy barrier of the intermediates O* and OOH* was significantly optimized. x / FeCrMo-NH 4 As the anode in alkaline water electrolysis, the F oxygen evolution catalyst showed excellent OER activity, requiring only low overpotentials of 208 mV and 239 mV to drive 10 mA cm -2 and 100mAcm -2 The current density is 41.0mVdec. -1, indicating that it has a fast catalytic rate and good reaction kinetics, with a Cdl of 8.38 mFcm -2 , indicating that it has the highest electrochemically active surface area. After ECSA normalization, NiTe x / FeCrMo-NH 4 F still has the best catalytic activity. From the EIS graph, we can see that NiTe x / FeCrMo-NH 4 F exhibits minimal charge transfer resistance and has excellent long-term stability at a current density of 500 mA cm -2 The stability can reach 1000h.

[0037] 4. NiTe of the present invention x / FeCrMo-NH 4 F catalyst is a non-precious metal composite material, and the raw materials used are easy to purchase, abundant in resources and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The NiTe of Example 1 of the present invention x / FeCrMo-NH 4 XRD pattern of material F;

[0039] Figure 2 The NiTe of Example 1 of the present invention x / FeCrMo-NH 4 SEM image of material F;

[0040] Figure 3 The NiTe of Example 1 of the present invention x / FeCrMo-NH 4 TEM image of material F;

[0041] Figure 4 The NiTe of Example 1 of the present invention x / FeCrMo-NH 4 HAADF-STEM image of F material;

[0042] Figure 5 The NiTe of Example 1 of the present invention x / FeCrMo-NH 4 XPS O1s pattern of F material;

[0043] Figure 6 The NiTe of Example 1 of the present invention x / FeCrMo-NH 4 Schematic diagram of the synthesis of F material;

[0044] Figure 7The NiTe of Example 1 of the present invention x / FeCrMo-NH 4 The OER performance of F material under 1 mol / L KOH, including linear sweep voltammetry curves at different speeds at a scan rate of 2 mV / s, overpotential bar graphs at different current densities, Tafel slope, double layer capacitance graph, ECSA normalized linear sweep voltammetry curve, TOF curve, EIS graph and stability test.

[0045] Figure 8 The NiTe x And NiTe prepared with different ligand sources M x LSV diagram of / FeCrMo-M catalyst; from Figure 8 It can be seen that NiTe x / FeCrMo-NH 4 F has the best performance, but the performance of the catalysts regulated by other ligand sources and other metals is stronger than that of NiTe x . DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the embodiments, but they are not intended to limit the present invention.

[0047] Embodiments of the present invention

[0048] Embodiment 1:

[0049] NiTe x / FeCrMo-NH 4 The preparation method of F material comprises the following steps:

[0050] 1) Before use, the nickel foam was cleaned with acetone, ethanol, hydrochloric acid and deionized water in sequence, and dried in a vacuum drying oven at 60°C for 9h;

[0051] 2) Weigh 2mmol Na 2 TeO 3 Dissolve in 50 mL of deionized water, stir for 30 minutes, add 5 mL of hydrazine hydrate dropwise to the solution, and continue stirring for 30 minutes;

[0052] 3) The mixed solution was transferred to a 100 mL polytetrafluoroethylene reactor liner, a piece of pretreated nickel foam was placed in the reactor liner, and the mixture was reacted in an oven at 180°C for 24 h. After cooling to room temperature, the nickel foam was taken out, rinsed with deionized water and ethanol for 3 times, and then placed in a vacuum drying oven at 60°C for 9 h to obtain NiTe x -original;

[0053] 4) Add 50 mg NH4 F, 75 mg Fe(NO 3 ) 3 9H 2 O, 75 mg Na 2 MoO 4 ·2H 2 O and 75 mg Cr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0054] 5) NiTe obtained in step 3) x -original samples were activated by cyclic voltammetry (CV) in the electrolyte prepared in step 4) to obtain NiTe x -original was used as the working electrode, the carbon rod was used as the counter electrode, Hg / HgO was used as the reference electrode, the CV scanning voltage range was -0.1 to 1.0 V (vs. Hg / HgO), the scanning rate was 50 mV / s, the scanning number was 200, and then it was rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60 °C for 9 h, and a ligand-regulated oxygen evolution catalyst was obtained, named: NiTe x / FeCrMo-NH 4 F.

[0055] In this example, NiTe x / FeCrMo-NH 4 Taking F material as an example, its structure was determined by X-ray diffractometer.

[0056] like Figure 1 As shown, the diffraction peak positions are respectively consistent with the NiTe phase (JCPDS#01-089-7179) and Ni 10.35 Te 7.97 The diffraction peaks of the NiTe phase (JCPDS#00-019-0846) match the peaks of the NiTe phase (JCPDS#00-019-0846). x The phase is a mixture of the two. The peaks at 30.9°, 42.7°, 45.7°, 56.2° and 58.1° correspond to the (101), (102), (110), (201) and (103) planes of NiTe (JCPDS#01-089-7179), respectively. The peaks at 27.1°, 28.8°, 29.8°, 33.9°, 35.4°, 37.0°, 39.3°, 45.1° and 46.3° correspond to Ni 10.35 Te 7.97(JCPDS#00-019-0846) (111), (004), (022), (023), (121), (104), (114), (025) and (200) faces. Due to the low crystallinity of NiOOH, no peak of NiOOH was observed in XRD. The content of Fe, Cr and Mo elements in the material structure after in-situ reconstruction is very low, so the peaks of Fe, Cr and Mo elements are not observed in XRD.

[0057] NiTe x / FeCrMo-NH 4 Scanning diagram of F( Figure 2 ) The rough surface of the nanosheet structure can be clearly seen.

[0058] Furthermore, through transmission electron microscopy ( Figure 3 ) can further confirm the nanosheet structure, and clear lattice fringes can be seen, with a lattice spacing of and Corresponding to Ni 10.35 Te 7.97 The (111) crystal plane of the NiTe phase and the (101) crystal plane of the NiTe phase have a lattice spacing of and Corresponding to the (111) and (011) crystal planes of NiOOH (JCPDS#27-956) phase.

[0059] HAADF-STEM Figure 4 ) shows that the elements Ni, Te, Fe, Cr and O are evenly distributed in NiTe x / FeCrMo-NH 4 F nanosheets, indicating the successful doping of elements Fe and Cr. Mo was not observed due to its large atomic radius, high valence, large migration barrier, and difficulty in entering the lattice.

[0060] XPS fine spectrum of O1s ( Figure 5 ) shows NiTe x / FeCrMo-NH 4 F has abundant oxygen vacancies.

[0061] In this example, NiTe x / FeCrMo-NH 4 The electrocatalytic oxygen evolution performance of F was measured by Chenhua CHI660E workstation. x / FeCrMo-NH 4 The F electrode was used as the working electrode, Hg / HgO as the reference electrode, and the carbon rod as the counter electrode. A KOH solution with a concentration of 1 mol / L was injected into the electrolytic cell as the electrolyte to form a three-electrode test system.

[0062] The NiTe prepared in this example x / FeCrMo-NH 4 F is taken as an example, and its OER performance is as follows Figure 7 As shown in the figure, the linear sweep voltammetry test results performed at a scan rate of 2 mV / s in a 1 mol / L KOH solution show that only low overpotentials of 208 mV and 239 mV are required to drive 10 mA cm -2 and 100mAcm -2 The current density is 41.0mVdec. -1 , indicating that it has a fast catalytic rate and good reaction kinetics, C dl 8.38mFcm -2 , indicating that it has the highest electrochemically active surface area. The calculated ECSA is used to normalize the LSV curve of the sample to measure the intrinsic activity of the material. After ECSA normalization, NiTe x / FeCrMo-NH 4 F still has the best catalytic activity. From the EIS graph, we can see that NiTe x / FeCrMo-NH 4 F exhibits the smallest charge transfer impedance, indicating that it has more ideal electron transport and faster reaction kinetics. The stability is tested by chronopotentiometry at a current density of 500 mA cm -2 Under this condition, the stability can reach 1000h, showing extraordinary stability.

[0063] Embodiment 2:

[0064] NiTe x / The preparation method of FeCrMo-KSCN material comprises the following steps:

[0065] 1) Before use, the nickel foam was cleaned with acetone, ethanol, hydrochloric acid and deionized water in sequence, and dried in a vacuum drying oven at 60°C for 9h;

[0066] 2) Weigh 2mmol Na 2 TeO 3 Dissolve in 50 mL of deionized water, stir for 30 minutes, add 5 mL of hydrazine hydrate dropwise to the solution, and continue stirring for 30 minutes;

[0067] 3) The mixed solution was transferred to a 100 mL polytetrafluoroethylene reactor liner, a piece of pretreated nickel foam was placed in the reactor liner, and the mixture was reacted in an oven at 180°C for 24 h. After cooling to room temperature, the nickel foam was taken out, rinsed with deionized water and ethanol for 3 times, and then placed in a vacuum drying oven at 60°C for 9 h to obtain NiTex -original;

[0068] 4) Add 50 mg KSCN, 75 mg Fe(NO 3 ) 3 9H 2 O, 75 mg Na 2 MoO 4 ·2H 2 O and 75 mg Cr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0069] 5) NiTe obtained in step 3) x -original samples were activated by cyclic voltammetry (CV) in the electrolyte prepared in step 4) to obtain NiTe x -original was used as the working electrode, the carbon rod was used as the counter electrode, Hg / HgO was used as the reference electrode, the CV scanning voltage range was -0.1-1.0V (vs. Hg / HgO), the scanning rate was 50mV / s, the scanning number was 200, and then it was rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60℃ for 9h, and a ligand-regulated oxygen evolution catalyst was obtained, named: NiTe x / FeCrMo-KSCN.

[0070] The NiTe prepared in this example x / FeCrMo-KSCN material as an example, the linear sweep voltammetry test results performed at a scan rate of 2mV / s in 1mol / LKOH solution showed that at a current density of 10mA / cm 2 and 100mA / cm 2 Under the condition of , the overpotentials are 218mV and 250mV respectively.

[0071] Embodiment 3:

[0072] NiTe x / FeCrMo-K 3 [Fe(CN) 6 ] The method for preparing the material comprises the following steps:

[0073] 1) Before use, the nickel foam was cleaned with acetone, ethanol, hydrochloric acid and deionized water in sequence, and dried in a vacuum drying oven at 60°C for 9h;

[0074] 2) Weigh 2mmolNa 2 TeO 3Dissolve in 50 mL of deionized water, stir for 30 minutes, add 5 mL of hydrazine hydrate dropwise to the solution, and continue stirring for 30 minutes;

[0075] 3) The mixed solution was transferred to a 100 mL polytetrafluoroethylene reactor liner, a piece of pretreated nickel foam was placed in the reactor liner, and the mixture was reacted in an oven at 180°C for 24 h. After cooling to room temperature, the nickel foam was taken out, rinsed with deionized water and ethanol for 3 times, and then placed in a vacuum drying oven at 60°C for 9 h to obtain NiTe x -original;

[0076] 4) Add 50 mg K to 1 mol / L KOH solution 3 [Fe(CN) 6 ], 75mgFe(NO 3 ) 3 9H 2 O, 75mgNa 2 MoO 4 ·2H 2 O and 75mgCr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0077] 5) NiTe obtained in step 3) x -original samples were activated by cyclic voltammetry (CV) in the electrolyte prepared in step 4) to obtain NiTe x -original was used as the working electrode, the carbon rod was used as the counter electrode, Hg / HgO was used as the reference electrode, the CV scanning voltage range was -0.1-1.0V (vs. Hg / HgO), the scanning rate was 50mV / s, the scanning number was 200, and then it was rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60℃ for 9h, and a ligand-regulated oxygen evolution catalyst was obtained, named: NiTe x / FeCrMo-K 3 [Fe(CN) 6 ].

[0078] The NiTe prepared in this example x / FeCrMo-K 3 [Fe(CN) 6 ] material as an example, the linear sweep voltammetry test results performed at a scan rate of 2mV / s in a 1mol / LKOH solution showed that at a current density of 10mA / cm 2 and 100mA / cm 2 Under the condition of , the overpotentials are 222mV and 258mV respectively.

[0079] Embodiment 4:

[0080] NiTe x / FeCrMo-NH 4 The preparation method of F material comprises the following steps:

[0081] 1) Before use, the nickel foam was cleaned with acetone, ethanol, hydrochloric acid and deionized water in sequence, and dried in a vacuum drying oven at 50°C for 9h;

[0082] 2) Weigh 1.5mmol Na 2 TeO 3 Dissolve in 50 mL of deionized water, stir for 20 minutes, add 2.5 mL of hydrazine hydrate dropwise to the solution, and continue stirring for 20 minutes;

[0083] 3) The mixed solution was transferred to a 100 mL polytetrafluoroethylene reactor liner, a piece of pretreated nickel foam was placed in the reactor liner, and the reaction was carried out in a 150°C oven for 30 h. After cooling to room temperature, the nickel foam was taken out, rinsed with deionized water and ethanol for 3 times, and then placed in a 50°C vacuum drying oven for 9 h to obtain NiTe x -original;

[0084] 4) Add 50 mg NH 4 F, 50mg Fe(NO 3 ) 3 9H 2 O, 50 mg Na 2 MoO 4 ·2H 2 O and 50mg Cr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0085] 5) NiTe obtained in step 3) x -original samples were activated by cyclic voltammetry (CV) in the electrolyte prepared in step 4) to obtain NiTe x -original was used as the working electrode, the carbon rod was used as the counter electrode, Hg / HgO was used as the reference electrode, the CV scanning voltage range was -0.1-1.0V (vs. Hg / HgO), the scanning rate was 50mV / s, the scanning number was 200, and then it was rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60℃ for 9h, and a ligand-regulated oxygen evolution catalyst was obtained, named: NiTe x / FeCrMo-NH 4 F.

[0086] Embodiment 5:

[0087] NiTe x / FeCrMo-NH 4 The preparation method of F material comprises the following steps:

[0088] 1) Before use, the nickel foam was cleaned with acetone, ethanol, hydrochloric acid and deionized water in sequence, and dried in a vacuum drying oven at 70°C for 8 h;

[0089] 2) Weigh 2.5mmol Na 2 TeO 3 Dissolve in 50 mL of deionized water, stir for 40 minutes, add 7.5 mL of hydrazine hydrate dropwise to the solution, and continue stirring for 40 minutes;

[0090] 3) The mixed solution was transferred to a 100 mL polytetrafluoroethylene reactor liner, a piece of pretreated nickel foam was placed in the reactor liner, and the mixture was reacted in a 200°C oven for 20 h. After cooling to room temperature, the nickel foam was taken out, rinsed with deionized water and ethanol for 3 times, and then placed in a 70°C vacuum drying oven for 8 h to obtain NiTe x -original;

[0091] 4) Add 50 mg NH 4 F, 100 mg Fe(NO 3 ) 3 9H 2 O, 100mgNa 2 MoO 4 ·2H 2 O and 100 mg Cr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0092] 5) NiTe obtained in step 3) x -original samples were activated by cyclic voltammetry (CV) in the electrolyte prepared in step 4) to obtain NiTe x -original was used as the working electrode, the carbon rod was used as the counter electrode, Hg / HgO was used as the reference electrode, the CV scanning voltage range was -0.1-1.0V (vs. Hg / HgO), the scanning rate was 50mV / s, the scanning number was 200, and then it was rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60℃ for 9h, and a ligand-regulated oxygen evolution catalyst was obtained, named: NiTe x / FeCrMo-NH 4 F.

[0093] Embodiment 6:

[0094] NiTe x The preparation method of the FeCrMo material comprises the following steps:

[0095] 1) Before use, the nickel foam was cleaned with acetone, ethanol, hydrochloric acid and deionized water in sequence, and dried in a vacuum drying oven at 60°C for 9h;

[0096] 2) Weigh 2mmolNa 2 TeO 3 Dissolve in 50 mL of deionized water, stir for 30 minutes, add 5 mL of hydrazine hydrate dropwise to the solution, and continue stirring for 30 minutes;

[0097] 3) The mixed solution was transferred to a 100 mL polytetrafluoroethylene reactor liner, a piece of pretreated nickel foam was placed in the reactor liner, and the mixture was reacted in an oven at 180°C for 24 h. After cooling to room temperature, the nickel foam was taken out, rinsed with deionized water and ethanol for 3 times, and then placed in a vacuum drying oven at 60°C for 9 h to obtain NiTe x -original;

[0098] 4) Add 75 mg Fe(NO 3 ) 3 9H 2 O, 75mgNa 2 MoO 4 ·2H 2 O and 75mgCr(NO 3 ) 3 9H 2 O, an electrolyte with a red precipitate is obtained;

[0099] 5) NiTe obtained in step 3) x -original samples were activated by cyclic voltammetry (CV) in the electrolyte prepared in step 4) to obtain NiTe x -original was the working electrode, the carbon rod was the counter electrode, Hg / HgO was the reference electrode, the CV scanning voltage range was -0.1-1.0V (vs.Hg / HgO), the scanning rate was 50mV / s, the scanning number was 200, and then it was rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60℃ for 9h, and the oxygen evolution catalyst was obtained, named: NiTe x / FeCrMo.

[0100] The NiTe prepared in this example x / FeCrMo material as an example, the linear sweep voltammetry test results performed at a scan rate of 2mV / s in a 1mol / LKOH solution showed that at a current density of 10mA / cm 2 and 100mA / cm2 Under the condition of , the overpotentials are 240mV and 298mV respectively.

[0101] Embodiment 7:

[0102] NiTe x The method for preparing the material comprises the following steps:

[0103] 1) Before use, the nickel foam was cleaned with acetone, ethanol, hydrochloric acid and deionized water in sequence, and dried in a vacuum drying oven at 60°C for 9h;

[0104] 2) Weigh 2mmolNa 2 TeO 3 Dissolve in 50 mL of deionized water, stir for 30 minutes, add 5 mL of hydrazine hydrate dropwise to the solution, and continue stirring for 30 minutes;

[0105] 3) The mixed solution was transferred to a 100 mL polytetrafluoroethylene reactor liner, a piece of pretreated nickel foam was placed in the reactor liner, and the mixture was reacted in an oven at 180°C for 24 h. After cooling to room temperature, the nickel foam was taken out, rinsed with deionized water and ethanol for 3 times, and then placed in a vacuum drying oven at 60°C for 9 h to obtain NiTe x -original;

[0106] 4) NiTe obtained in step 3) x -original samples were activated by cyclic voltammetry (CV) in 1 mol / L KOH electrolyte to obtain NiTe x -original was the working electrode, the carbon rod was the counter electrode, Hg / HgO was the reference electrode, the CV scanning voltage range was -0.1-1.0V (vs.Hg / HgO), the scanning rate was 50mV / s, the scanning number was 200, and then it was rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60℃ for 9h, and the oxygen evolution catalyst was obtained, named: NiTe x .

[0107] The NiTe prepared in this example x For example, the linear sweep voltammetry test results of the material in 1 mol / L KOH solution at a scan rate of 2 mV / s showed that at a current density of 10 mA / cm 2 and 100mA / cm 2 Under the condition of , the overpotentials are 387mV and 470mV respectively.

[0108] Embodiment 8:

[0109] NiO / FeCrMo-NH 4 The preparation method of F material comprises the following steps:

[0110] 1) Add 50 mg NH 4 F, 75 mg Fe(NO 3 ) 3 9H 2 O, 75 mg Na 2 MoO 4 ·2H 2 O and 75 mg Cr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0111] 2) Activating NiO by cyclic voltammetry (CV) in the electrolyte prepared in step 1), with NiO as the working electrode, the carbon rod as the counter electrode, and Hg / HgO as the reference electrode, the CV scanning voltage range is -0.1 to 1.0 V (vs. Hg / HgO), the scanning rate is 50 mV / s, the scanning number is 200, and then rinsed with deionized water and ethanol, placed in a vacuum drying oven at 60° C. for 9 hours, and a ligand-regulated oxygen evolution catalyst is obtained, named: NiO / FeCrMo-NH 4 F.

[0112] Embodiment 9:

[0113] NiS 2 / FeCrMo-NH 4 The preparation method of F material comprises the following steps:

[0114] 1) Add 50 mg NH 4 F, 75 mg Fe(NO 3 ) 3 9H 2 O, 75 mg Na 2 MoO 4 ·2H 2 O and 75 mg Cr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0115] 2) NiS 2 Cyclic voltammetry (CV) activation was performed in the electrolyte prepared in step 1) to obtain NiS 2The working electrode, the carbon rod was the counter electrode, and Hg / HgO was the reference electrode. The CV scanning voltage range was -0.1 to 1.0 V (vs. Hg / HgO), the scanning rate was 50 mV / s, and the number of scanning circles was 200. Then, it was rinsed with deionized water and ethanol, and placed in a vacuum drying oven at 60 ° C for 9 h to obtain a ligand-regulated oxygen evolution catalyst, named: NiS 2 / FeCrMo-NH 4 F.

[0116] Embodiment 10:

[0117] NiSe 2 / FeCrMo-NH 4 The preparation method of F material comprises the following steps:

[0118] 1) Add 50 mg NH 4 F, 75 mg Fe(NO 3 ) 3 9H 2 O, 75 mg Na 2 MoO 4 ·2H 2 O and 75 mg Cr(NO 3 ) 3 9H 2 O, a red clear electrolyte is obtained;

[0119] 2) NiSe 2 Cyclic voltammetry (CV) activation was performed in the electrolyte prepared in step 1) to obtain NiSe 2 The working electrode, the carbon rod was the counter electrode, and Hg / HgO was the reference electrode. The CV scanning voltage range was -0.1 to 1.0 V (vs. Hg / HgO), the scanning rate was 50 mV / s, and the number of scanning circles was 200. Then it was rinsed with deionized water and ethanol, and placed in a vacuum drying oven at 60 ° C for 9 h to obtain a ligand-regulated oxygen evolution catalyst named: NiSe 2 / FeCrMo-NH 4 F.

[0120] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for ligand-regulated surface reconstruction of an oxygen evolution catalyst, characterized in that: The steps include: S1. The nickel foam was washed with acetone, ethanol, hydrochloric acid and water in turn and dried for later use; S2. Dissolve Na2TeO3 in water, then add hydrazine hydrate and stir evenly to obtain liquid A; S3. The nickel foam is placed in a reactor, and then the liquid A is transferred to the reactor, heated to react, and the reaction is naturally cooled to room temperature after completion; S4. Take out the nickel foam from S3, rinse it with water and ethanol in turn, and then dry it to obtain the precatalyst NiTe x -original; S5. Adding a ligand source, Fe(NO3)3·9H2O, Na2MoO4·2H2O and Cr(NO3)3·9H2O to a KOH solution to obtain an electrolyte; S6. The precatalyst NiTe obtained in S4 x -original was placed into the electrolyte obtained from S5 for cyclic voltammetry activation, then rinsed with water and ethanol in turn, and finally dried to obtain a ligand-regulated oxygen evolution catalyst.

2. The method for ligand-regulated surface reconstruction of oxygen evolution catalyst according to claim 1, characterized in that: In the S2, the molar concentration of Na2TeO3 in the A solution is 30-50mmol / L, the volume ratio of hydrazine hydrate to water is 0.5-1.5:10; and the stirring time is 20-40min.

3. The method for ligand-regulated surface reconstruction of oxygen evolution catalyst according to claim 1, characterized in that: The heating temperature in S3 is 150-200° C., and the reaction time is 20-30 h.

4. The method for ligand-regulated surface reconstruction of oxygen evolution catalyst according to claim 1, characterized in that: The drying temperature in S1, S4 and S6 is 50-70°C and the drying time is 8-9h.

5. The method for ligand-regulated surface reconstruction of oxygen evolution catalyst according to claim 1, characterized in that: The concentration of the KOH solution in S5 is 0.8-1.2 mol / L, and the mass ratio of the ligand source, Fe(NO3)3·9H2O, Na2MoO4·2H2O and Cr(NO3)3·9H2O is 1:1-2:1-2:1-2.

6. The method for ligand-regulated surface reconstruction of oxygen evolution catalyst according to claim 1, characterized in that: The ligand source in S5 is one of NH4F, KSCN or K3[Fe(CN)6].

7. The method for ligand-regulated surface reconstruction of oxygen evolution catalyst according to claim 1, characterized in that: The cyclic voltammetry described in S6 is specifically based on NiTe x -original was the working electrode, carbon rod was the counter electrode, and Hg / HgO was the reference electrode; the CV scanning voltage range was -0.1-1.0 V, the scanning rate was 50 mV / s, and the number of scanning cycles was 200 cycles.

8. The method for ligand-regulated surface reconstruction of oxygen evolution catalyst according to claim 1, characterized in that: The precatalyst NiTe in S6 x -original is replaced by one of NiO, NiS2 or NiSe2.

9. A ligand-regulated oxygen evolution catalyst prepared by the method according to any one of claims 1 to 8.

10. Use of the ligand-regulated oxygen evolution catalyst according to claim 9 in catalytic oxygen evolution reaction.

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