MoS2 nanosheets decorated Ni(OH)2 nanorod array for active overall water splitting

Abstract

Integrating heterogeneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts into compatible composite catalysts with specific interfaces and structures holds great promise for the development of efficient bifunctional catalysts for overall water splitting. Herein, heterogeneous MoS2-Ni(OH)2 catalyst supported by Ni foam (MoS2@Ni(OH)2/NF) is developed, in which the Ni(OH)2 nanorod array is grafted with MoS2 nanosheets. The hierarchical 1D/2D structures benefit not only the exposure of catalytic site but also the facilitated charge transfer. The heterointerfaces allow the synergism of electric structure modulation for improved catalytic activity and kinetics towards HER, OER, and overall water splitting. MoS2@Ni(OH)2/NF achieves a current density of 10 mA cm−2 at low overpotentials of 134 and 233 mV for HER and OER in 1 M KOH, respectively. Moreover, a cell voltage as low as 1.46 V is obtained to afford 10 mA cm−2 in a tow-electrode electrolyzer using MoS2@Ni(OH)2/NF as bifunctional catalysts, assuring it superior to most of the reported noble-metal-free bifunctional electrocatalysts. Such heterogeneous design of composite catalyst should shed light on the exploration of functional materials for energy applications.