FeCoNiWV-based catalysts via pulse electrodeposition for high-performance hydrogen evolution

FeCoNiWV-based catalysts were synthesized via pulse electrodeposition onto nickel foam substrates, with systematic modulation of deposition voltage and pulse on/off durations. The relationship between deposition parameters and the resulting structural and electrochemical properties of the catalyst was thoroughly investigated. Structural characterization indicated that optimized pulse conditions led to improved surface features and favorable nanostructures, which increase the number of active sites and facilitate charge transfer. Electrochemical analysis in 0.5 M H₂SO₄ revealed that the catalyst fabricated under –1.3 V with a pulse duration of 0.8 s on and 0.2 s off exhibited the lowest overpotential (37 mV at –10 mA/cm²) and a low Tafel slope of 34 mV/dec, indicative of rapid hydrogen evolution kinetics. The low charge-transfer resistance (0.7492 Ω) and large double-layer capacitance (627 μF/cm²) confirmed efficient electron transport and a high density of active sites. Furthermore, the catalyst showed enhanced stability during a 100 h stability test under the optimal pulse regime, highlighting the importance of pulse control in tailoring both catalytic activity and durability. This work underscores the potential of pulse electrodeposition as a versatile strategy for engineering FeCoNiWV-based HER catalysts and provides valuable insights for the rational design of next-generation electrocatalytic materials for sustainable hydrogen production.