Abstract
Nickel (Ni) alloys are low-cost materials with good electrocatalytic activity for the hydrogen evolution reaction (HER) in alkaline water electrolysis. The electrode cost can be further reduced by using alloys with a porous structure, providing high surface area with low catalyst amounts. Herein, transition metal 3D nanoporous foams based on Ni, copper (Cu), and cobalt (Co) alloys are produced over stainless steel substrates. The metallic foams are obtained by galvanostatic electrodeposition using hydrogen bubble evolution as a dynamic template. Their morphology and chemical composition is analyzed by SEM and EDS, respectively. Linear scan voltammetry in 8 M KOH solutions are used to study the HER at the Ni-Cu/Co electrodes at room temperature. Additional chronoamperometry measurements show good stability of the tested foam electrodes. The results suggest that the 3D electrocatalysts can attain high HER efficiencies while using low metal amounts. Moreover, their low-cost, one-step fabrication method presents several advantages over conventional procedures