Synergistically Coupled CoMo/CoMoP Electrocatalyst for Highly Efficient and Stable Overall Water Splitting

Finding reservoir-rich and efficient bifunctional electrocatalysts for water splitting is key to further sustainable energy development. Transition metal phosphides (TMPs) are extensively exploited as effective electrocatalysts, but the construction of strong coupling interfaces to improve catalytic performance by simple methods is still a bottleneck. Here, we designed and prepared a novel heterostructure electrocatalyst composed of cobalt-molybdenum (CoMo) alloy particles integrated with CoMoP nanosheets via the method of template-assisted conversion, followed by electrodeposition. Thanks to the strong interfacial coupling and synergistic effect between CoMo alloy particles and CoMoP nanosheets, the prepared CoMo/CoMoP/NF shows outstanding activity with overpotentials of only 29 mV for the hydrogen evolution reaction (HER) and 246 mV for the oxygen evolution reaction (OER) in 1 M KOH at a current density of 10 mA cm-2. Furthermore, the assembled CoMo/CoMoP || CoMo/CoMoP electrode can attain 10 mA cm-2 with a low battery voltage of 1.54 V. This study offers a valuable reference to the construction of bimetallic alloy/bimetallic phosphide heterostructure electrocatalysts, which applies to the large-scale application of electrocatalytic energy conversion technology.