Controlled growth of porous oxygen-deficient NiCo2O4 nanobelts as high-efficiency electrocatalysts for oxygen evolution reaction

Abstract

Owing to their distinctive chemical properties and cost-effectiveness, transition metal oxides (TMOs) promise intriguing potential in electrocatalysis applications. Herein, porous NiCo₂O₄ nanobelts with controlled oxygen deficiencies were synthesized based on a facile strategy of hydrothermal growth followed by annealing under an inert atmosphere. By finely adjusting annealing temperature and time, concentrations of oxygen deficiencies within the nanobelts could be modulated. The oxygen-deficient NiCo₂O₄ nanobelts exhibit superior oxygen evolution reaction (OER) performance at a relatively low overpotential which is superior to the values of prepared pristine NiCo₂O₄ electrocatalysts. In particular, they show excellent stability for 10 h at 10 mA cm⁻². The enhanced OER activity and stability of the catalyst can be ascribed to the abundant oxygen deficiencies as well as porous architecture of the anisotropic nanobelts. This work paves a promising way in fabricating advanced electrocatalysts.