Designing and Tuning the Electronic Structure of Nickel-Vanadium Layered Double Hydroxides for Highly Efficient Oxygen Evolution Electrocatalysis br

Abstract

Despite the considerable efforts in advancing nonpre-cious-metal candidates as oxygen evolution reaction (OER) electro-catalysts, cost-effective production of efficient and stable catalysts viasimple synthesis routes remains to be realized. We report on theexperimental and density functional theory (DFT) guidelines of nickel(Ni)-vanadium (V) layered double hydroxides (LDHs) to prepare anoptimal electrocatalyst by changing its composition ratio. Theoptimized Ni0.75V0.25LDH exhibits the ultralow overpotentials of 200and 292 mV at the current densities of 10 and 400 mA cm-2,respectively, a long-term durability of more than 100 h at 10 mA cm-2,and an extremely low Tafel slope of 48.3 mV dec-1. Thesefindings canprovide guidance for the facile optimal design of state-of-the-art wateroxidation catalysts by using LDHs for large-scale practical applications. The enhanced catalytic performance can be attributed to alower hydrogen desorption energy and the presence of many open O sites, which can promote the initiation of the OER reaction.