Silver-decorated amorphous cobalt hydr(oxy)oxide as highly active catalyst for oxygen evolution reaction

Abstract

“Soft” and “flexible” amorphous materials have gained traction recently due to their self-adjustability toward environmental changes. Unfortunately, poor conductivity and limited stability seriously hamper their commercial applications. In this work, we develop an Ag-decorated amorphous and efficient oxygen evolution reaction (OER) catalyst, requiring overpotentials of only 170 and 250 mV to yield current densities of 10 and 100 mA cm−2 in a 1.0 M KOH solution, respectively. The catalyst also exhibits outstanding stability, maintaining 93.1% of its initial performance after 27 h of continuous testing. When used as an air-electrode catalyst in a zinc-air battery, it recorded a charge–discharge cycle life of 330 h at a current density of 5 mA cm−2, with a voltage gap of 0.87 V. And the Ag decoration induced better electrical conductivity, more active specific surface, and higher Co3+ content are found to be the proper reasons for the catalyst’s outstanding OER performance and stability.