ABSTRACT
The development of active and cost-effective bifunctional catalysts is crucial for water dissociation through electrolysis. In this study, bifunctional catalysts with Ni nanoparticles (NPs) anchored on MoO2 nanorods have been synthesized via in situ dissolution of NiMoO4-ZIF under an inert atmosphere without using hydrogen gas. The Ni-MoO2 catalyst exhibits high electrocatalytic activity by modulating the calcination temperature. Benefitingfrom the MOF transformation and accompanying Ni particles' outward diffusion, a precisely designed interface heterostructure between Ni and MoO2 was constructed. As a result, the optimized Ni-MoO2 catalyst achieves extremely low overpotentials of only 24 mV and 275 mV at 10 mA cm-2 for the hydrogen evolution reaction and oxygen evolution reaction, respectively. Furthermore, the catalyst required a small cell voltage of 1.55 V to deliver a current density of 10 mA cm-2 and remained stable over 20 h for overall water splitting. The proposed MOF-derived heterojunction protocol provides a general approach for designing and fabricating transition metal oxide catalysts for water electrolysis.
