Nest-like Ag-doped NiMoO4/NF with rich oxygen vacancies as robust catalysts for highly efficient oxygen evolution

Abstract

The development of low-cost and highly efficient electrocatalysts for oxygen evolution reaction (OER) with good conductivity, high specific surface area and abundant oxygen vacancies is of great significance for the future renewable energy conversion and storage system. Herein, Ag doped NiMoO4 materials on the Ni foam (NiMoO4/Ag/NF) with rich oxygen vacancies were successfully prepared by hydrothermal strategy and layer by layer assembly method. The Ag ions are doped in-situ to promote electron transfer and compensate for the poor conductivity of metal oxides. The suitable air annealing treatment is used to create rich oxygen vacancies. The high specific surface area and one-dimensional characteristics of the cross mesoporous nanorod skeleton are responsible for the increased exposure of active centers and the rapid charge transfer behavior. The NiMoO4/Ag/NF exhibits high activity for OER in alkaline solution (an overpotential of 275 mV at the current density of 20 mA cm−2) and low Tafel slope (53.67 mV dec−1), and a satisfying durability in 1.0 M KOH. This study provides an effective method for the preparation of Ag doped one-dimensional nanomaterials with excellent OER catalytic performance and electrochemical stability.