Engineering active sites on hierarchical transition bimetal oxides/sulfides heterostructure array enabling robust overall water splitting

Rational design of the catalysts is impressive for sustainable energy conversion. However, there is a grand challenge to engineer active sites at the interface. Herein, hierarchical transition bimetal oxides/sulfides heterostructure arrays interacting two-dimensional MoOx/MoS2 nanosheets attached to one-dimensional NiOx/Ni3S2 nanorods were fabricated by oxidation/hydrogenation-induced surface reconfiguration strategy. The NiMoOx/NiMoS heterostructure array exhibits the overpotentials of 38mV for hydrogen evolution and 186mV for oxygen evolution at 10mAcm(-2), even surviving at a large current density of 500mAcm(-2) with long-term stability. Due to optimized adsorption energies and accelerated water splitting kinetics by theory calculations, the assembled two-electrode cell delivers the industrially relevant current densities of 500 and 1000mAcm(-2) at record low cell voltages of 1.60 and 1.66V with excellent durability. This research provides a promising avenue to enhance the electrocatalytic performance of the catalysts by engineering interfacial active sites toward large-scale water splitting. While water splitting is an appealing carbon-neutral strategy for renewable energy generation, there is a need to develop new active, cost-effective catalysts. Here, authors prepare a nickel-molybdenum oxide/sulfide heterojunctions as bifunctional H-2 and O-2 evolution electrocatalysts.