Molybdenum and Phosphorous Dual‐Doped, Transition‐Metal‐Based, Free‐Standing Electrode for Overall Water Splitting

Water splitting using earth‐abundant, low‐cost, highly efficient, transition‐metal‐based electrocatalysts with high activity and stability is inevitable for sustainable energy development. Herein, a molybdenum (Mo) and phosphorous (P) co‐doped highly efficient and durable electrocatalyst is grown on nickel foam (P‐NiCo 2 O 4 /CoMoO 4 /NF, for simplicity G‐3) for hydrogen and oxygen evolution reactions (HER and OER, respectively). The dual doping of Mo and P prompts the formation of nanosheet array structures and modifies the surface electronic states, which subsequently enhance the active sites, facilitate the charge transfer, and accelerate the reaction kinetics. As a result, the G‐3 sample requires a low overpotential of 78.7 mV and 248.6 mV to reach a current density of 25 mA cm −2 for the HER and OER, respectively. Furthermore, a cell voltage of 1.729 V is required at 100 mA cm −2 , and the catalyst demonstrates long‐term stability of 54 h for overall water splitting.