Preparation method and application of Fe-doped defect-rich CuO-coated FeCoO and CuO-coated CuxS / FeCoS self-supporting electrode
By preparing Fe-doped defect-rich CuO@FeCoO and CuO@CuxS/FeCoS self-supporting electrodes, the problems of slow kinetics and poor stability of anode and cathode materials for water electrolysis were solved, high-efficiency electrocatalytic activity and stability were achieved, and the synthesis strategy of catalytic materials for water electrolysis reactions was broadened.
Patent Information
- Application Number
- CN202510913267.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-03
- Publication Date
- 2025-09-26
AI Technical Summary
The existing anode and cathode materials for water electrolysis have slow kinetics and poor stability, and the existing precious metal catalysts are expensive and difficult to achieve bifunctional catalysis.
The preparation method of Fe-doped defect-rich CuO@FeCoO and CuO@CuxS/FeCoS free-standing electrodes is adopted. By combining chemical oxidation-electrodeposition-plasma etching-ion exchange, free-standing electrodes with high specific surface area and rich defect sites are prepared.
It achieves high electrocatalytic activity and stability of the water electrolysis reaction, broadens the synthesis strategy of anode and cathode catalytic materials, and improves the efficiency of water electrolysis.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of water electrolysis and new energy materials, and in particular relates to a Fe-doped defect-rich CuO@FeCoO and CuO@Cu x Preparation method and application of S / FeCoS self-supporting electrode. Background Art
[0002] Electrochemical water splitting technology has attracted widespread attention due to its high efficiency in producing high-purity hydrogen. The key issue is that the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in water electrolysis are kinetics-slow, which requires efficient electrocatalysts. Currently, Ru and Ir-based oxides for OER and Pt-based composites for HER are still the catalysts with the best electrochemical performance in the process of hydrogen production by water electrolysis. However, due to the low abundance and high cost of these commercial catalysts, their industrial application is greatly limited. Therefore, people have been working on developing low-cost and highly active alternative catalysts.
[0003] Transition metal compounds are considered to be a class of potential catalytic materials due to their low price, simple synthesis and easy modification. Among them, the multivalent characteristics of transition metal oxides (TMOs) can effectively regulate the reaction activity under a wide range of pH conditions, showing excellent OER catalytic performance. For example, cobalt, nickel and manganese-based oxide materials have become research hotspots in this field due to their high earth abundance and significant catalytic efficiency. In particular, the OER catalytic activity of cobalt-based oxides is comparable to that of precious metal Ru and Ir-based catalysts. In addition, transition metal sulfide compounds (TMCs) exhibit unique HER catalytic advantages, which is mainly due to their moderate proton adsorption free energy and optimized electronic band structure, which can effectively reduce the reaction energy barrier and accelerate the kinetic process. It is worth noting that this type of material not only has excellent catalytic activity, but also has a simple synthesis process and controllable physicochemical properties.
[0004] In addition, developing effective strategies to improve the catalytic activity of water electrolysis catalytic materials is of great significance, but it also faces many challenges. Heteroatom doping is considered to be an effective means to enhance intrinsic activity by changing the electronic structure of the catalyst surface, but it is only used to unilaterally regulate a single catalyst and it is difficult to achieve bifunctionalization. In addition, defect engineering is also a feasible strategy that can regulate the electronic structure and surface properties of electrocatalysts to improve their electrocatalytic activity. Among them, oxygen vacancies (O v ) are the most popular and widely studied defect type due to their low formation energy and their potential to enhance the bifunctional activity of electrocatalysts. Summary of the Invention
[0005] The main purpose of the present invention is to provide a Fe-doped defect-rich CuO@FeCoO and CuO@Cu x The preparation method and application of S / FeCoS self-supporting electrode are used to solve the problems of slow kinetics and poor stability of existing anode and cathode materials for water electrolysis.
[0006] According to an embodiment of the present invention, a Fe-doped defect-rich CuO@FeCoO and CuO@Cu x The preparation method and application of S / FeCoS self-supporting electrode include: placing pretreated copper foam in a mixed solution of potassium hydroxide or sodium hydroxide and ammonium persulfate at a certain concentration for a period of time to obtain a Cu(OH)2 array electrode; placing the Cu(OH)2 array electrode in a cobalt salt and ferrous salt-based electrolyte solution, and electro-depositing at a specific potential to obtain a Cu(OH)2@FeCo-LDH self-supporting electrode; placing the electrode in a plasma enhanced chemical vapor deposition tube furnace, and etching for a certain time to obtain a CuO@FeCoO self-supporting electrode; placing the electrode in an alkali metal sulfide, and immersing for a certain time to obtain a CuO@Cu x S / FeCoS free-standing electrode.
[0007] The concentration of potassium hydroxide or sodium hydroxide is 1 to 3 M, the concentration of ammonium persulfate is 0.05 to 0.15 M, and the reaction time is 10 to 60 min.
[0008] The cobalt salt includes but is not limited to cobalt nitrate, cobalt sulfate, and cobalt chloride; the solution concentration is 10 to 40 mM; the deposition potential is -0.9 to -1.5 V vs. RHE; and the electrodeposition time is 60 to 600 s.
[0009] The ferrous salt includes but is not limited to ferrous chloride, ferrous nitrate, and ferrous sulfate, with a concentration of 10 to 40 mM; the electrodeposition potential is -0.9 to -1.5 V vs. RHE; and the electrodeposition time is 60 to 600 s.
[0010] The plasma etching conditions are as follows: the gas condition is an O2 atmosphere, the pressure is 0.1-0.3 Torr, the furnace temperature is room temperature to 100°C, the radio frequency (RF) power is set to 100-300W, and the etching time is 0.5h-2h.
[0011] The alkali metal sulfide includes but is not limited to sodium sulfide and potassium sulfide, the solution concentration is 10-100 mM, and the immersion time is 0.5 h-4 h.
[0012] According to an embodiment of the present invention, there is also provided a Fe-doped defect-rich CuO@FeCoO and CuO@Cu prepared according to the above-mentioned preparation method. xS / FeCoS self-supporting electrode, applied to the anode and cathode reactions of water electrolysis.
[0013] According to the technical solution of the present invention, by combining chemical oxidation-electrodeposition-plasma etching-ion exchange, the self-supporting electrode obtained has a high specific surface area and abundant defect sites, exhibits excellent electrocatalytic activity and stability, and broadens the synthesis strategy of anode and cathode catalytic materials for water electrolysis reaction. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the embodiments of the present invention, the drawings related to the embodiments are briefly introduced below.
[0015] Figure 1 a is the XRD spectra of the samples prepared in Example 1, Comparative Example 1 and Comparative Example 2, Figure 1 b is the XRD spectra of the samples prepared in Example 2 and Comparative Example 3.
[0016] Figure 2 This is the SEM image of the sample prepared in Example 1.
[0017] Figure 3 This is the TEM image of the sample prepared in Example 2.
[0018] Figure 4 The EPR spectra of the samples prepared in Example 1 and Example 2 are shown.
[0019] Figure 5 a is the OER performance LSV curve of the samples prepared in Example 1, Comparative Example 1 and Comparative Example 2 in N2-saturated 1M KOH electrolyte. Figure 5 b is the LSV curve of the HER performance of the samples prepared in Example 1, Example 2 and Comparative Example 3 in N2-saturated 1M KOH electrolyte.
[0020] Figure 6 The graph shows the electrolysis water test results of the samples prepared in Example 1 and Example 2. DETAILED DESCRIPTION
[0021] The present invention will be described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative work are all within the scope of protection of the present invention.
[0022] Example 1:
[0023] A method for preparing a Fe-doped defect-rich CuO@FeCoO self-supporting electrode mainly comprises the following steps:
[0024] (1) The copper foam was sequentially ultrasonically treated with deionized water, acetone, dilute hydrochloric acid, and anhydrous ethanol and dried naturally. It was then placed in a mixed solution of 2.5 M potassium hydroxide and 0.125 M ammonium persulfate for 30 min to in situ grow Cu(OH)2NWs on the copper foam.
[0025] (2) The chronoamperometric electrodeposition was performed on Cu(OH)2NWs. During the deposition process, a saturated calomel electrode (SCE) was used as the reference electrode, a graphite sheet was used as the counter electrode, the deposition solution was a mixed solution of 30 mM cobalt nitrate hexahydrate and 10 mM ferrous sulfate heptahydrate, and the deposition time was 600 s to obtain Cu(OH)2@FeCo-LDH NWs.
[0026] (3) The Cu(OH)2@FeCo-LDH NWs electrode was placed in a plasma enhanced chemical vapor deposition tube furnace. The gas conditions were O2 atmosphere, the pressure was 0.15 Torr, the furnace temperature was room temperature (25°C), the radio frequency power (RF) was set to 200 W, and the etching time was 1 h to obtain CuO@FeCoO v NWs self-supporting electrodes.
[0027] Example 2:
[0028] In this embodiment, CuO@FeCoO v The NWs were further placed in a 50 mM sodium sulfide solution for 3 h to obtain CuO@Cu x S / FeCoS NWs free-standing electrode.
[0029] Comparative Example 1:
[0030] The experimental steps of this embodiment are the same as those of embodiment 1, except that 10 mM ferrous sulfate heptahydrate is not added to the electrodeposition solution.
[0031] Comparative Example 2:
[0032] The experimental steps of this example are the same as those of Example 1, except that the Cu(OH)2@FeCo-LDH NWs electrode is calcined in a muffle furnace at a heating rate of 5°C / min, a heating temperature of 400°C, and a holding time of 1 h to obtain a CuO@FeCoO NWs self-supporting electrode.
[0033] Comparative Example 3:
[0034] The experimental steps of this embodiment are the same as those of embodiment 2, with the only difference being that no electrodeposition is performed, and plasma etching and sulfurization reaction are performed on the Cu(OH)2NWs.
[0035] Figure 1a is the XRD pattern of the samples prepared in Example 1, Comparative Example 1 and Comparative Example 2; it can be seen from the figure that diffraction peaks of CuO and CoO appear, while no Fe phase is observed in Example 1 and Comparative Example 2, indicating that Fe is doped into the samples. Figure 1 b is the XRD pattern of the samples prepared in Example 2 and Comparative Example 3; the peak of CuO can still be seen in the figure, and the diffraction peaks of CuS and Cu2S appear at the same time, indicating that part of the oxide is converted into sulfide. In addition, the peak of CoS can also be observed, indicating that CuO@Cu x S / FeCoS NWs composite electrode.
[0036] Figure 2 This is an SEM image of the sample prepared in Example 1; as can be seen from the figure, Example 1 exhibits a three-dimensional nanoarray electrode structure, which can increase more effective specific surface area, promote contact between the electrolyte and the electrode, optimize the electron transmission path, and thus improve the activity of the catalyst.
[0037] Figure 3 The TEM image of the sample prepared in Example 2 shows that the lattice spacings of different parts are 0.183, 0.206, 0.26, and 0.267 nm, respectively, corresponding to the CuS (006), CuO (111), CoS (102), and Cu2S (364) crystal planes, which once again confirms the synthesis of CuO@Cu x S / FeCoS NWs composite electrode materials.
[0038] Figure 4 The EPR spectra of the samples prepared in Example 1 and Example 2 show a g value of approximately 2.003, confirming the presence of oxygen vacancies. By comparison, it is found that more vacancies can be generated after sulfurization.
[0039] Figure 5 a is the OER performance LSV curve of the samples prepared in Example 1, Comparative Example 1 and Comparative Example 2 in N2 saturated 1M KOH electrolyte. As can be seen from the figure, Example 1 has the best OER performance, which is -2 The corresponding voltage is the minimum (1.54V). Figure 5 b is the LSV curve of HER performance of the samples prepared in Example 1, Example 2 and Comparative Example 3 in N2 saturated 1M KOH electrolyte. As can be seen from the figure, the HER performance of Example 2 is the best, and its HER performance is the best at a current of 100mA·cm -2 The corresponding voltage is the smallest, which is 193mV.
[0040] Figure 6a and b are test results of the samples of Example 1 and Example 2 assembled into a full water electrolysis cell as cathode / anode catalyst. Figure 6 a, 10 and 100 mA·cm -2 The cell voltages at 10 and 20 mA cm were 1.64 and 1.76 V, respectively, and exhibited a faster reaction kinetics, which was better than that reported in most literatures. -2 Long-term stability test was carried out under alternating current density ( Figure 6 b), it can be seen that as the current density changes, the corresponding potential can also remain stable, showing excellent long-term operation capability.
[0041] It should be noted that the above embodiments are only for further illustrating the present invention and should not be construed as limiting the present invention. Without departing from the spirit and substance of the present invention, modifications or replacements made to the methods, steps or conditions of the present invention are within the scope of the present invention.
Claims
1. A Fe-doped defect-rich CuO@FeCoO and CuO@Cu x Preparation method and application of S / FeCoS self-supporting electrode, characterized in that The following steps are involved: S1: placing the pretreated copper foam in a mixed solution of potassium hydroxide or sodium hydroxide and ammonium persulfate at a certain concentration for a period of time to prepare a Cu(OH)2 array electrode; S2: placing the Cu(OH)2 array electrode in a cobalt salt and ferrous salt-based electrolyte solution, and electrodepositing the Cu(OH)2@FeCo-LDH self-supporting electrode at a specific potential; S3: placing the Cu(OH)2@FeCo-LDH self-supporting electrode in a plasma enhanced chemical vapor deposition tube furnace and etching for a certain time to obtain a CuO@FeCoO self-supporting electrode; S4: Place the CuO@FeCoO self-supporting electrode in an alkali metal sulfide solution and immerse it for a certain period of time to obtain CuO@Cu x S / FeCoS free-standing electrode.
2. The preparation method according to claim 1, wherein: In step S1, the concentration of potassium hydroxide or sodium hydroxide is 1-3 M, the concentration of ammonium persulfate is 0.05-0.15 M; and the reaction time is 10-60 min.
3. The preparation method according to claim 1, wherein: In step S2, the cobalt salt includes but is not limited to cobalt nitrate, cobalt sulfate, and cobalt chloride; the solution concentration is 10 to 40 mM; the deposition potential is -0.9 to -1.5 V vs. RHE; and the electrodeposition time is 60 to 600 s.
4. The preparation method according to claim 1, wherein: In step S2, the ferrous salt includes but is not limited to ferrous chloride, ferrous nitrate, and ferrous sulfate, with a concentration of 10 to 40 mM; the electrodeposition potential is -0.9 to -1.5 V vs. RHE; and the electrodeposition time is 60 to 600 s.
5. The preparation method according to claim 1, wherein: In step S3, the gas condition is O2 atmosphere, the pressure is 0.1-0.3 Torr, the furnace temperature is room temperature to 100°C, the radio frequency (RF) power is set to 100-300W, and the etching time is 0.5h-2h.
6. The preparation method according to claim 1, wherein: In step S4, the alkali metal sulfide includes but is not limited to sodium sulfide and potassium sulfide, the solution concentration is 10-100 mM, and the immersion time is 0.5 h-4 h.
7. The Fe-doped defect-rich CuO@FeCoO self-supporting electrode and CuO@Cu prepared by the preparation method according to any one of claims 1 to 6 x S / FeCoS self-supporting electrode material.
8. The Fe-doped defect-rich CuO@FeCoO and CuO@Cu according to claim 7 x Application of S / FeCoS self-supporting electrodes in water electrolysis and new energy materials.