Hornwort-like hollow porous MoO3/NiF2 heterogeneous nanowires as high-performance electrocatalysts for efficient water oxidation

Abstract

Designing and constructing stable and affordable electrocatalysts with unique micro-morphology and interface for oxygen evolution reaction (OER) is crucial for efficient water splitting. Herein, self-supported and hollow porous MoO3/NiF2 heterogeneous nanowires for excellent OER catalytst have been designed via an advanced top-down strategy. Fluorinating the precursor nanowires of NiMoO4 successfully activates the Ni sites in the material and constructs porous MoO3/NiF2 heterogeneous nanowires. The hollow nanowires with abundant porous structure provide large specific surface area, while the heterogeneous interfaces cause rich electro-active sites to facilitate the electron transfer, which contribute to the significant improvement in the OER performance of the material in alkaline solution. Consequently, the catalysts of hollow porous MoO3/NiF2 nanowires grown on Ni foam deliver a current density of 100 mA cm−2 with the overpotential of 272 mV in OER and exhibit a good durability of 50 h at high current density of 100 mA cm−2. This study further proves that the reasonable micro-morphology construction and interface engineering design can boost up the electrocatalytic activities.