Self-supported NiMoP2 nanowires on carbon cloth as an efficient and durable electrocatalyst for overall water splitting

Abstract

Designing and exploring efficient and stable non-noble bifunctional catalysts by nanostructure modification and chemical composition tuning for water splitting is of critical importance for sustainable resources. Herein, pure phase nickel molybdenum phosphide (NiMoP₂) nanowires on carbon cloth are successfully synthesized through a simple and highly reproducible in situ P/O exchange process. Such a NiMoP₂ nanowire catalyst requires low overpotentials of 199 and 330 mV to obtain a high current density of 100 mA cm⁻² towards the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, and is among the most active HER and OER electrocatalysts yet reported. The bifunctional NiMoP₂ is used as both anode and cathode catalysts in a two-electrode water electrolysis configuration, which delivers a current density of 10 mA cm⁻² under a potential of 1.67 V. Furthermore, the overall water-splitting of the bifunctional NiMoP₂ nanowire catalyst is further driven by a dry battery with a nominal voltage of 1.5 V which exhibits excellent performance and durability in a strong alkaline electrolyte.