Direct sodium borohydride-maleic acid fuel cell and its electrode applications

Abstract

The application discloses a direct sodium borohydride-maleic acid fuel cell (DBMAFC) and application of electrodes thereof. The direct sodium borohydride-maleic acid fuel cell is assembled by using a CoMo@NiC2O4 / NF anode and a Pb / CP cathode; a nickel is loaded on a nickel foam by using an electrodeposition method, then nickel oxalate is formed by etching with oxalic acid, finally, a CoMo compound is co-deposited on the surface of the nickel oxalate to obtain the CoMo@NiC2O4 / NF electrode; and the Pb / CP electrode is obtained by loading lead on carbon paper by using the electrodeposition method. The electrode material prepared by the application has a special three-dimensional nanoflower structure and provides abundant active sites; no organic binder is added in the process of preparing the electrode, so that good conductivity of the electrode is ensured; the addition of molybdenum can make the dispersibility of cobalt better, so that more active sites are exposed, and the synergistic effect between cobalt and molybdenum is utilized to improve the NaBH4 electro-oxidation performance, so that the electrode becomes a very promising electrode; and the raw materials required by the application can be regenerated, and are widely sourced and low in price.

Description

Technical Field

[0001] This invention relates to a direct sodium borohydride-maleic acid fuel cell and its electrode application, belonging to the fields of electrocatalysis and fuel cells. Background Technology

[0002] Energy is a vital material foundation for human survival and the lifeline of national economic development, but the amount of energy available to humanity is dwindling. Therefore, many scholars are dedicated to finding a renewable energy source to address the current predicament. Fuel cells can directly convert the chemical energy in fuels and oxidants into electrical energy. Among them, direct borohydride fuel cells (DBFCs) are a popular research topic with great development potential. Borohydrides, due to their high hydrogen content, are excellent hydrogen storage materials. Sodium borohydride (NaBH4), in particular, has a hydrogen content as high as 10.6 wt.%; it exists in solid form, making it easy to transport; theoretically, NaBH4 undergoes an 8e reaction in alkaline solution. - The electro-oxidation reaction is shown in the following formula. Therefore, fuel cells using NaBH4 as fuel have good development potential.

[0003]

[0004] Initially, DBFCs mainly consisted of direct sodium borohydride-oxygen fuel cells (DBOFCs) and direct sodium borohydride-hydrogen peroxide fuel cells (DBHPFCs). These used oxygen as the oxidant and produced 4E. - The reduction reaction is slow, affecting battery efficiency. Using hydrogen peroxide as the oxidant, a 2e⁻ reaction occurs. - The reduction reaction has a low activation overpotential, and its product is water, so its economic efficiency needs to be improved. C4H4O4, also known as maleic acid (MA), is a dicarboxylic acid that can undergo an electroreduction reaction (see the formula below). As an oxidant for fuel cells, its product, succinic acid (C4H6O4), is a widely used chemical with high application prospects.

[0005] .

[0006] The performance of a fuel cell largely depends on the electrocatalytic activity of the anode and cathode. Electrocatalytic activity can be improved by adjusting the structure and composition of the electrode catalysts. Literature review has found that molybdenum incorporation can prevent catalyst agglomeration, resulting in uniform dispersion of active materials on the electrode surface and a higher specific surface area. DH Duan et al. (DH Duan, XL Yin, JK Zhao, et al. Performance study of amorphous NiBalloys modified by Mo as electrocatalysts for borohydride oxidation[J]. Ionics, 2022, 28(3): 1377-1386.) prepared Ni-B-Mo. x The catalyst was investigated to study the effect of Mo doping on the electro-oxidation reaction of NaBH4. The results showed that adding Mo can improve the dispersibility of Ni-B / C, thereby exposing more active sites. However, the prepared Ni-B-Mo... x The catalytic performance remains low. It is well known that lead (Pb) can effectively catalyze the electroreduction reaction of C4H4O4. A paper published by Shen Haiping et al. (Shen Haiping, Zhao Fengming, Xu Yinghua et al. Research progress in electrolytic synthesis of succinic acid [J]. Chemical Industry and Engineering Progress, 2009, 28(01).) reviewed the research progress in electrolytic synthesis of C4H6O4, clarifying the advantages of Pb electrodes in the electrolytic synthesis of C4H6O4: high hydrogen evolution overpotential, cheap and readily available raw materials, and good conductivity. However, the utilization rate of Pb plates is not high, which limits its development. Summary of the Invention

[0007] This invention aims to provide a direct sodium borohydride-maleic acid fuel cell and its electrode applications, including a method for preparing a CoMo@NiC2O4 / NF electrode and its application in catalyzing the electro-oxidation of sodium borohydride; a method for preparing a Pb / CP electrode and its application in catalyzing the electro-reduction of maleic acid; and the assembly of a direct sodium borohydride-maleic acid fuel cell using a CoMo@NiC2O4 / NF electrode as the anode and a Pb / CP electrode as the cathode, followed by a performance study.

[0008] This invention proposes a novel direct sodium borohydride-maleic acid fuel cell (DBMAFC), using NaBH4 as fuel and C4H4O4 as oxidant. During DBMAFC operation, after the electrochemical reaction is completed, the reaction product in the cathode region is C4H6O4, enabling the fuel cell to synthesize useful chemical products while releasing electrical energy, which has profound significance for fuel cell research. This invention also prepares CoMo@NiC2O4 / NF and Pb / CP electrodes with special structures and compositions, improving their catalytic performance by adjusting the electrode structure and composition.

[0009] This invention provides a method for preparing a CoMo@NiC2O4 / NF electrode, which involves loading nickel onto nickel foam using electrodeposition, etching with oxalic acid, and finally co-depositing CoMo onto its surface to obtain the CoMo@NiC2O4 / NF electrode.

[0010] The preparation method of the above CoMo@NiC2O4 / NF electrode specifically includes the following steps: (1) Use nickel foam (10 mm × 10 mm) as the electrode support; (2) Using the nickel foam from step (1) as the working electrode, the platinum sheet as the counter electrode, and the Ag / AgCl (saturated KCl) electrode as the reference electrode, place it in a solution containing 0.1 mol·dm³. -3 NiSO4·6H2O and 0.1 mol·dm -3 In a mixed solution of C6H5Na3O7, a Ni / NF electrode was prepared by deposition at a potential of -5.0 V for 600 s using a potentiostatic method; (3) The Ni / NF electrode prepared in (2) was placed in a solution containing 0.5 mol·dm³ -3 NiC2O4 / NF electrode was prepared by standing in H2C2O4 solution for 12 h. (4) Place the NiC2O4 / NF electrode obtained in step (3) in a solution containing 0.01 mol·dm -3 CoSO4·7H2O, 0.20 mol·dm -3 C6H5Na3O7, 5×10 -5 mol·dm -3 CH3(CH2) 11 OSO2Na, 0.05 mol·dm -3 (NH4)2SO4 and 0.001~0.005 mol·dm -3In a mixed solution of Na₂MoO₄·2H₂O, using a NiC₂O₄ / NF electrode as the working electrode, a constant current method was employed at -600 mA·cm⁻¹. -2 At a current density of 300 s, a CoMo@NiC2O4 / NF electrode was obtained by deposition.

[0011] The present invention also provides a CoMo@NiC2O4 / NF electrode prepared by the above preparation method.

[0012] This invention also provides the application of the aforementioned CoMo@NiC2O4 / NF electrode in the electrocatalytic oxidation of NaBH4. The specific application process is as follows: In a three-electrode system, CoMo@NiC2O4 / NF is used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl (saturated KCl) electrode as the reference electrode. Linear sweep voltammetry is used to characterize the NaBH4 electrooxidation reaction catalyzed by the CoMo@NiC2O4 / NF electrode. The scan range of the linear sweep voltammetry is -1.2 to -0.2 V, and the scan rate is 10 mV·s. -1 The test solution concentration was 0.5–2.5 mol·dm³. -3 NaOH and 0.02~0.60 mol·dm -3 NaBH4.

[0013] The present invention also provides a method for preparing a Pb / CP electrode, wherein lead is loaded onto carbon paper by electrodeposition to obtain a Pb / CP electrode.

[0014] The preparation method of the above-mentioned Pb / CP electrode specifically includes the following steps: (1) Use carbon paper as an electrode support; (2) Using the carbon paper from step (1) as the working electrode, the platinum sheet as the counter electrode, and the Ag / AgCl (saturated KCl) electrode as the reference electrode, place it in a solution containing 0.1~0.3 mol·dm³. -3 PbB2F8 and 0.01 mol·dm -3 In a mixed solution of H3BO3, a Pb / CP electrode was obtained by applying a constant potential square wave method with a cyclic potential of ±1 V for 10 s each time, and repeating the cycle 10 times. This electrode was used to catalyze the electroreduction of C4H4O4.

[0015] The present invention also provides a Pb / CP electrode prepared by the above preparation method.

[0016] This invention also provides the application of the above-mentioned Pb / CP electrode in the electrocatalytic reduction of C4H4O4.

[0017] The above application process is as follows: In a three-electrode system, Pb / CP is used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl (saturated KCl) electrode as the reference electrode. Linear sweep voltammetry is used to characterize the electroreduction reaction of C4H4O4 catalyzed by the Pb / CP electrode. The scanning range of the linear sweep voltammetry is -1.0 to 0 V, and the scanning rate is 10 mV·s. -1 The test solution was 1.0 mol·dm³. -3 H2SO4 and 0.02~0.30 mol·dm -3 C4H4O4.

[0018] A DBMAFC was assembled using a CoMo@NiC2O4 / NF electrode as the anode and a Pb / CP electrode as the cathode. The reaction solution in the fixed anode region was 1.0 mol·dm³. -3 NaOH and 0.5 mol·dm -3 A mixed solution of NaBH4 was used, with the reaction solution in the fixed cathode region at a concentration of 1.0 mol·dm³. -3 H2SO4 and 0.2 mol·dm -3 A mixed solution of C4H4O4 was prepared by adjusting the reaction flow rate (2~7 mL·min). -1 Study its characteristics.

[0019] The beneficial effects of this invention are: (1) The electrode material prepared by this invention has a special three-dimensional nanoflower-like structure, which provides abundant active sites; (2) No organic binder was added during the preparation of the electrode in this invention, which ensures the good conductivity of the electrode; (3) All raw materials required for this invention are renewable, widely available, and inexpensive; (4) The addition of molybdenum can improve the dispersion of cobalt, thereby exposing more active sites, and the synergistic effect between cobalt and molybdenum can improve the electro-oxidation performance of NaBH4, making it a very promising electrode. (5) The present invention is equipped with a novel DBMAFC, which can recover the reaction product C4H6O4 in the cathode area while generating electricity. Attached Figure Description

[0020] Figure 1 Linear sweep voltammetry curves of the NiC2O4 / NF (curve a), Co@NiC2O4 / NF (curve b), and CoMo@NiC2O4 / NF (curve c) electrodes in Example 1.

[0021] Figure 2 The CoMo@NiC2O4 / NF electrodes in Examples 2 and 3 were tested at 1.0 mol·dm³. -3NaOH and 0.3 mol·dm -3 In a mixed solution of NaBH4 (curve a), 1.0 mol·dm -3 NaOH and 0.5 mol·dm -3 Linear sweep voltammetry curve (curve b) in NaBH4 mixed solution.

[0022] Figure 3 The linear sweep voltammetry curves of the CP (curve a) and Pb / CP (curve b) electrodes in Example 4 are shown.

[0023] Figure 4 The Pb / CP electrode in Example 5 was used at 1.0 mol·dm³. -3 H2SO4 and 0.2 mol·dm -3 Linear sweep voltammetry curves of a C4H4O4 mixed solution.

[0024] Figure 5 This is a schematic diagram of the DBMAFC assembled with CoMo@NiC2O4 / NF and Pb / CP electrodes in Example 6.

[0025] Figure 6 The reaction solution flow rate is 2 mL / min. -1 (Curve a) The flow rate of the reaction solution is 5 mL·min -1 (Curve b) and the reaction liquid flow rate is 7 mL·min -1 (Curve c) shows the polarization curve and power density curve of DBMAFC.

[0026] Figure 7 FT-IR for the recovered cathode reaction product C4H6O4.

[0027] Figure 5 In the diagram: 1 is the Pb / CP electrode, 2 is the CoMo@NiC2O4 / NF electrode, 3 is the current collector, 4 is the end plate, 5 is the carbon plate, 6 is the Nafion 117 film, 7 is the sealing gasket, and 8 is the insulating sheet. Detailed Implementation

[0028] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments. Example 1

[0029] Method for preparing CoMo@NiC2O4 / NF electrodes: (1) Use nickel foam (10 mm × 10 mm) as the electrode support; (2) Using the nickel foam from step (1) as the working electrode, the platinum sheet as the counter electrode, and the Ag / AgCl (saturated KCl) electrode as the reference electrode, place it in a solution containing 0.1 mol·dm³. -3 NiSO4·6H2O and 0.1 mol·dm -3 Ni / NF electrodes were prepared by deposition at -5.0 V for 600 s in a mixed solution of C6H5Na3O7 using a potentiostatic method. (3) Place the Ni / NF electrode prepared in (2) in a solution containing 0.5 mol·dm -3 NiC2O4 / NF electrode was prepared by standing in H2C2O4 solution for 12 h. (4) Place the NiC2O4 / NF electrode obtained in step (3) in a solution containing 0.01 mol·dm -3 CoSO4·7H2O, 0.20 mol·dm -3 C6H5Na3O7, 5×10 -5 mol·dm -3 CH3(CH2) 11 OSO2Na, 0.05 mol·dm -3 (NH4)2SO4 and 0.003 mol·dm -3 In a mixed solution of Na₂MoO₄·2H₂O, using a NiC₂O₄ / NF electrode as the working electrode, a constant current method was employed at -600 mA·cm⁻¹. -2 At a current density of 300 s, a CoMo@NiC2O4 / NF electrode was obtained by deposition.

[0030] In a conventional three-electrode system, NiC2O4 / NF, Co@NiC2O4 / NF, and CoMo@NiC2O4 / NF electrodes were used as working electrodes, respectively; a platinum sheet electrode was used as the counter electrode; and an Ag / AgCl (saturated KCl) electrode was used as the reference electrode. The system was tested at 1.0 mol·dm³. -3 NaOH and 0.1 mol·dm -3 Linear sweep voltammetry was performed in a NaBH4 mixed solution, with a scan range of -1.2 to -0.2 V and a scan rate of 10 mV·s. -1 . Figure 1 Linear sweep voltammetry curves for NiC2O4 / NF, Co@NiC2O4 / NF, and CoMo@NiC2O4 / NF electrodes are shown. At a potential of -0.52 V, the oxidation current density generated by the CoMo@NiC2O4 / NF electrode is 199.34 mA·cm⁻¹. -2 This is significantly higher than that of the NiC2O4 / NF electrode (0.38 mA·cm). -2) and Co@NiC2O4 / NF electrode (129.64 mA·cm -2 This indicates that the CoMo@NiC2O4 / NF electrode has greater catalytic activity. Example 2

[0031] The CoMo@NiC2O4 / NF electrode prepared in Example 1 was used for the electrocatalytic oxidation of NaBH4. In a conventional three-electrode system, a CoMo@NiC2O4 / NF electrode is used as the working electrode, a platinum sheet electrode as the counter electrode, and an Ag / AgCl (saturated KCl) electrode as the reference electrode. The electrode is set at 1.0 mol·dm³. -3 NaOH and 0.3 mol·dm -3 Linear sweep voltammetry was performed in a NaBH4 mixed solution, with a scan range of -1.2 to -0.2 V and a scan rate of 10 mV·s. -1 When the potential is -0.2 V, the oxidation current density reaches 341.79 mA·cm⁻¹. -2 . Example 3

[0032] The CoMo@NiC2O4 / NF electrode prepared in Example 1 was used for the electrocatalytic oxidation of NaBH4. In a conventional three-electrode system, a CoMo@NiC2O4 / NF electrode is used as the working electrode, a platinum sheet electrode as the counter electrode, and an Ag / AgCl (saturated KCl) electrode as the reference electrode. The electrode is set at 1.0 mol·dm³. -3 NaOH and 0.5 mol·dm -3 Linear sweep voltammetry was performed in a NaBH4 mixed solution, with a scan range of -1.2 to -0.2 V and a scan rate of 10 mV·s. -1 . Figure 2 The NaBH4 concentration in the test solution for the CoMo@NiC2O4 / NF electrode was 0.3 mol·dm³. -3 (Curve a corresponds to Example 2) and 0.5 mol·dm -3 (Curve b corresponds to the linear sweep voltammetry curve of Example 3). When the potential is -0.2 V, the oxidation current density generated by the CoMo@NiC2O4 / NF electrode is 465.33 mA·cm⁻¹. -2 The concentration of NaBH4 in the test solution was higher than that of the CoMo@NiC2O4 / NF electrode at 0.3 mol·dm³. -3 The resulting current density indicates that increasing the NaBH4 concentration is beneficial to improving electrochemical performance. Example 4

[0033] Methods for preparing Pb / CP electrodes: (1) Use carbon paper as an electrode support; (2) Using the carbon paper from step (1) as the working electrode, the platinum sheet as the counter electrode, and the Ag / AgCl (saturated KCl) electrode as the reference electrode, place it in a solution containing 0.20 mol·dm³. -3 PbB2F8 and 0.01 mol·dm -3 In a mixed solution of H3BO3, a Pb / CP electrode was obtained by applying a constant potential square wave method with a cyclic potential of ±1 V for 10 s each time, and repeating the cycle 10 times. This electrode was used to catalyze the electroreduction of C4H4O4.

[0034] In a conventional three-electrode system, the CP electrode and Pb / CP electrode are used as working electrodes, the platinum sheet electrode as the counter electrode, and the Ag / AgCl (saturated KCl) electrode as the reference electrode, at 1.0 mol·dm³. -3 H2SO4 and 0.1 mol·dm -3 Linear sweep voltammetry was performed in a C4H4O4 mixed solution, with a scan range of -1.0 to 0 V and a scan rate of 10 mV·s. -1 . Figure 3 The figure shows the linear sweep voltammetry curves for the CP electrode and the Pb / CP electrode. It can be seen from the figure that the reduction current density generated by the Pb / CP electrode at a potential of -1.0 V is 187.32 mA·cm⁻¹. -2 This is greater than the reduction current density generated by the CP electrode (52.30 mA·cm⁻¹). -2 The oxidation current density of the Pb / CP electrode is much higher than that of the CP electrode, indicating that lead can better catalyze the electroreduction of C4H4O4. Example 5

[0035] The Pb / CP electrode prepared in Example 4 was used to catalyze the electroreduction of C4H4O4. In a conventional three-electrode system, a Pb / CP electrode is used as the working electrode, a platinum sheet electrode as the counter electrode, and an Ag / AgCl (saturated KCl) electrode as the reference electrode, at 1.0 mol·dm³. -3 H2SO4 and 0.2 mol·dm -3 Linear sweep voltammetry was performed in a C4H4O4 mixed solution, with a scan range of -1.0 to 0 V and a scan rate of 10 mV·s. -1 . Figure 4 The figure shows the linear sweep voltammetry curve of the Pb / CP electrode. It can be seen from the graph that the reduction current density generated by the Pb / CP electrode at a potential of -1.0 V is 232.78 mA·cm⁻¹. -2 Greater than 1.0 mol·dm -3 H2SO4 and 0.1 mol·dm-3 The reduction current density generated in the C4H4O4 mixed solution (187.32 mA·cm⁻¹) -2 This indicates that an increase in the concentration of C4H4O4 is beneficial to the electroreduction reaction. Example 6

[0036] Method for assembling a direct sodium borohydride-maleic acid fuel cell: The prepared CoMo@NiC2O4 / NF electrode was used as the anode, and the prepared Pb / CP electrode was used as the cathode to assemble a DBMAFC ( Figure 5 The reaction solution in the fixed anode region was 1.0 mol·dm³. -3 NaOH and 0.5 mol·dm -3 A mixed solution of NaBH4 was used, with the reaction solution in the fixed cathode region at a concentration of 1.0 mol·dm³. -3 H2SO4 and 0.2 mol·dm -3 The properties of DBMAFC were studied by varying the flow rate of the reaction solution in a mixed solution of C4H4O4.

[0037] Figure 6 The figures show the polarization and power density curves of DBMAFC at different flow rates. As can be seen from the figures, when the flow rate increases from 2 mL / min... -1 Increase to 5 mL·min -1 At that time, the power density was 20.55 mW·cm⁻¹ -2 Increased to 25.63 mW·cm -2 Increasing the flow rate allows for rapid fuel renewal on the electrode surface, making it easier for bubbles generated on the electrode surface to detach, thereby exposing more active sites on the electrode surface. When the flow rate is further increased to 7 mL / min... -1 At this point, the power density decreases because the higher flow rate causes the active material on the electrode surface to reach its carrying capacity limit, leading to more severe hydrolysis and self-decomposition of NaBH4, which in turn results in a decrease in power density.

[0038] The reaction solution in the cathode area is recovered and, through processes such as concentration, filtration, cooling, crystallization, and drying, the purified product C4H6O4 is obtained. Figure 7 FT-IR analysis of C4H6O4 confirmed that the recovered product was C4H6O4.

Claims

1. A direct sodium borohydride-maleic acid fuel cell, characterized in that: A direct sodium borohydride-maleic acid fuel cell was assembled using a CoMo@NiC2O4 / NF electrode as the anode and a Pb / CP electrode as the cathode, with the reaction solution in the anode region fixed at 1.0 mol·dm³. -3 NaOH and 0.5 mol·dm -3 A mixed solution of NaBH4 was used, with the reaction solution in the fixed cathode region at a concentration of 1.0 mol·dm³. -3 H2SO4 and 0.2 mol·dm -3 The characteristics of the battery were studied by changing the flow rate of the reaction solution in a mixed solution of C4H4O4, and the cathode product C4H6O4 was recovered. The specific steps in preparing the Pb / CP electrode are as follows: (1) Use carbon paper as an electrode support; (2) Using the carbon paper from step (1) as the working electrode, the platinum sheet as the counter electrode, and the Ag / AgCl electrode as the reference electrode, place it in a solution containing 0.1~0.3 mol·dm³. -3 PbB2F8 and 0.01 mol·dm -3 In a mixed solution of H3BO3, a Pb / CP electrode was obtained by applying a cyclic potential of ±1 V for 10 s and repeating the cycle 10 times using the constant potential square wave method.

2. The direct sodium borohydride-maleic acid fuel cell according to claim 1, characterized in that: The preparation method of CoMo@NiC2O4 / NF electrode is as follows: nickel is loaded onto nickel foam by electrodeposition, then nickel oxalate is formed by etching with oxalic acid, and finally CoMo composite is co-deposited onto its surface to obtain CoMo@NiC2O4 / NF electrode.

3. The direct sodium borohydride-maleic acid fuel cell according to claim 2, characterized in that: The preparation method of CoMo@NiC2O4 / NF electrode specifically includes the following steps: (1) Using nickel foam as an electrode support; (2) Using the nickel foam from step (1) as the working electrode, the platinum sheet as the counter electrode, and the Ag / AgCl electrode as the reference electrode, place it in a solution containing 0.1 mol·dm³. -3 NiSO4·6H2O and 0.1 mol·dm -3 Ni / NF electrodes were prepared by deposition at a potential of -5.0 V for 600 s in a mixed solution of C6H5Na3O7 using a potentiostatic method. (3) Place the Ni / NF electrode prepared in (2) in a solution containing 0.5 mol·dm -3 NiC2O4 / NF electrode was prepared by standing in H2C2O4 solution for 12 h. (4) Place the NiC2O4 / NF electrode obtained in step (3) in a solution containing 0.01 mol·dm -3 CoSO4·7H2O, 0.20 mol·dm -3 C6H5Na3O7, 5×10 -5 mol·dm -3 CH3(CH2) 11 OSO2Na, 0.05 mol·dm -3 (NH4)2SO4 and 0.001~0.005 mol·dm -3 In a mixed solution of Na₂MoO₄·2H₂O, using a NiC₂O₄ / NF electrode as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode, a galvanostatic method was employed at -600 mA·cm⁻¹. -2 At a current density of 300 s, a CoMo@NiC2O4 / NF electrode was obtained by deposition.

4. Application of a CoMo@NiC2O4 / NF electrode in the catalytic electro-oxidation of NaBH4.

5. The application according to claim 4, characterized in that... The application process is as follows: a conventional three-electrode system is used, with CoMo@NiC2O4 / NF as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode, at a concentration of 0.5~2.5 mol·dm³. -3 NaOH and 0.02~0.60 mol·dm -3 The NaBH4 solution was tested using linear sweep voltammetry with a scan range of -1.2 to -0.2 V and a scan rate of 10 mV·s. -1 .

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