MoS2 Nanosheets Uniformly Anchored on NiMoO4 Nanorods, a Highly Active Hierarchical Nanostructure Catalyst for OER and Pseudo-Capacitors

Hierarchical nanostructures have attracted considerable research attention due to their applications in the catalysis field. Herein, we design a versatile hierarchical nanostructure composed of NiMoO nanorods surrounded by active MoS nanosheets on an interconnected nickel foam substrate. The as-prepared nanostructure exhibits excellent oxygen evolution reaction performance, producing a current density of 10 mA cm at an overpotential of 90 mV, in comparison with 220 mV necessary to reach a similar current density for NiMoO. This behavior originates from the structural/morphological properties of the MoS nanosheets, which present numerous surface-active sites and allow good contact with the electrolyte. Besides, the structures can effectively store charges, due to their unique branched network providing accessible active surface area, which facilitates intermediates adsorptions. Particularly, NiMoO/MoS shows a charge capacity of 358 mAhg at a current of 0.5 A g (230 mAhg for NiMoO), thus suggesting promising applications for charge-storing devices.