| dc.description.abstract | This study employs microanode guided electroplating to fabricate three-dimensional nickel-zinc microcolumn electrodes. The electrochemical catalytic surface area of the electrodes is increased through the dissolution effect of zinc in an alkaline environment. Additionally, composite electroplating is used to embed 1T phase molybdenum disulfide (MoS₂) into the nickel-zinc alloy. The MoS₂ enhances the electrocatalytic edge active sites and optimizes the energy band structure, thereby improving the hydrogen evolution activity of the electrode.
The study investigates the composition ratio and electrochemical hydrogen evolution efficiency of nickel-zinc alloy microcolumns deposited with different concentrations of nickel chloride. Metal-phase MoS₂ is synthesized using the hydrothermal method, and a specific concentration is added to the nickel-zinc alloy plating solution. Composite electroplating is performed under a fixed bias of 3.6 V and a spacing of 60 µm to achieve the optimal hydrogen evolution performance of the nickel-zinc/MoS₂ composite electrode.
The microcolumns′ surface morphology is observed using electron microscopy, the chemical composition is analyzed by energy-dispersive spectroscopy, and the crystal structure is determined by X-ray diffraction. Finally, microcolumns embedded with different concentrations of 1T phase MoS₂ are immersed in a 1.0 M KOH solution, and electrochemical tests, including linear sweep voltammetry, cyclic voltammetry, electrochemical surface area measurement, chronopotentiometry, and electrochemical impedance spectroscopy, are conducted to evaluate their hydrogen evolution performance. The results indicate that the alloy composite microcolumns with 20 at.% MoS₂, 45 at.% nickel, and 35 at.% zinc exhibit the best hydrogen evolution efficiency, with the lowest Tafel slope (66 mV/dec), overpotential (η10 = -81 mV), and onset potential (Eonset = -0.66 V vs RHE), and a charge transfer resistance of 3.28 Ω·cm². Overall, the findings confirm that co-depositing MoS₂ with nickel-zinc alloy increases active sites and accelerates charge transfer, enhancing the electrocatalytic electrode′s hydrogen evolution performance. | en_US |