The Ni‐Mo‐S Catalyst @Copper Foams with Excellent Stability and 1.5 V Drive Electrolytic Water

Abstract The development of high‐efficiency, low‐cost, and long‐term stability catalysts for water electrolysis is significant for the sustainable production of hydrogen. The aim of this study is to reduce the overpotential and thus energy consumption. Toward this aim, transition metal sulfide catalyst (marked as S 5‐40 doped Ni 4 Mo) is successfully prepared by a fast one‐step electrodeposition process on a copper foam (CF) substrate. The S 20 doped Ni 4 Mo/CF catalyst displays an exceedingly low overpotential of 140 and −128 mV at 10 mA cm −2 for (oxygen evolution reaction) and (hydrogen evolution reaction), respectively. The S 20 doped Ni 4 Mo/CF can be powered by a commercial AA alkaline battery (1.5 V) in 1.0 m KOH. It shows a lower cell voltage of 1.595 V at 10 mA cm −2 for overall water splitting (OWS). Up to 60 h of stability testing, compared with the S 20 doped Ni 4 Mo/CF catalyst before electrolysis, their performance is improved by 15.5% and 41.1% at 2 and −0.7 V versus reversible hydrogen electrode, respectively. This study offers an avenue to fabricate transition metal sulfide bi‐functional catalysts for OWS and provides deep insights into the relationships among the S‐doping Ni 4 Mo at the 1.0 m KOH electrolyte physical characterization and electrocatalytic activity.