Electrodeposited Nickel–Tungsten Alloy Films With Multiporous Architecture for Hydrogen Evolution Reaction in Acidic Media

Porous Ni–W alloy films were fabricated by electrodeposition from a gluconate‐based electrolyte using three approaches: (i) micelle‐assisted deposition with Pluronic P‐123, (ii) colloidal crystal templating, and (iii) a combination of both. Hierarchically porous films were produced either by plating from a P‐123‐containing electrolyte onto substrates patterned with 200 nm polystyrene spheres, or from a P‐123‐free electrolyte onto substrates patterned with mixed 20 and 200 nm spheres. Dense Ni–W films were deposited under comparable conditions for reference. The tungsten content ranged from 1 to 19 wt.% depending on the method. All coatings were nanocrystalline single‐phase face‐centered cubic alloys, with diffraction peaks shifting to lower 2 θ values as W content increased. Electrochemical evaluation of the hydrogen evolution reaction in 0.5 M H 2 SO 4 revealed superior catalytic performance for the multiporous films templated with 20 and 200 nm spheres, achieving an overpotential ( η 10 ) of 300 mV versus reversible hydrogen electrode at −10 mA cm –2 and a Tafel slope of ∼134 mV dec –1 . The enhanced activity was attributed to the combined effect of high surface area and increased W content, while long‐term durability improved primarily with higher W content, as confirmed by 24 h potentiometry at −10 mA cm –2 .