Top-Down Preparation of Active Cobalt Oxide Catalyst

Cobalt oxide is a cheap catalyst for the oxygen evolution reaction; however, the low activity limits its practical application. Herein we report the preparation of a highly active Co₃O₄ catalyst via a top-down process, namely, laser fragmentation. The fierce laser irradiation generates fine and clean nanoparticles with abundant oxygen vacancies which simultaneously improve the adsorption energy and electrical conduction. As a result, the catalytic performance of the product reaches the top level of cobalt oxide, even outperforming the noble-metal catalyst, RuO₂