Silver decorated hydroxides electrocatalysts for efficient oxygen evolution reaction

Abstract

Electrocatalysts play a pivotal role in electrochemical water splitting, where the development of efficient oxygen evolution reaction (OER) electrocatalysts remains challenging. Here, we report a facile one-step blending approach to synthesize efficient and durable OER electrocatalysts of silver decorated hydroxides (Ag@hydroxides). The general efficacy of this methodology is demonstrated in five hydroxides, in form of powders or self-supported electrodes. The decoration of Ag lowers the overpotentials by 41–56 mV, rendering Ag@NiFe LDH among the most active OER catalysts. It requires an overpotential of 246 mV only to deliver a current density of 10 mA cm−2. Under industrial electrolysis conditions (30 wt% KOH and 80 °C), the cell voltage is 1.76 V for 500 mA cm−2. It is 270 mV lower than the intact nickel mesh, corresponding to a 9% improvement in the energy conversion efficiency. Furthermore, by combining spectroscopic analysis and theoretical calculation we unravel that the strong interfacial charge transfer is the root cause for the promoting catalytic activity, where the binding energies of catalytic intermediates are optimized. This work provides a facile and ease-to-scale-up approach for the synthesis of efficient and durable electrocatalysts and demonstrates the power of regulating the interface in improving electrocatalytic kinetics.