Tuning the electronic structure of NiCoVOx nanosheets through S doping for enhanced oxygen evolution.

It is of great importance to develop efficient and low-cost oxygen evolution reaction (OER) electrocatalysts for electrochemical water splitting. Herein, S doped NiCoVOx nanosheets grown on Ni-Foam (S-NiCoVOx/NF) with a modified electronic structure have been prepared through a facile one-step hydrothermal method. The as-prepared S4.06-NiCoVOx/NF exhibits outstanding OER activity with low overpotentials of 248 mV and 289 mV to deliver current densities of 10 mA cm-2 and 100 mA cm-2, respectively, and a small Tafel slope of 46.2 mV dec-1 in 1.0 M KOH electrolyte. These values are much lower than those obtained for most of the recently reported non-noble metal-based electrocatalysts under similar experimental conditions. This study provides a simple approach to rational design of efficient and cost-effective OER electrocatalysts for practical application of electrochemical water splitting.