Phosphorus-triggered synergy of phase transformation and chalcogenide vacancy migration in cobalt sulfide for an efficient oxygen evolution reaction.

Introduction of surface defects and phase control engineering in the electrocatalytic system of overall water splitting has played a crucial role in significantly enhancing its electrocatalytic activity toward the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in water splitting, but the relationship between structure and electrocatalysis is still elusive. Herein, we report a solid-liquid method to induce surface reorganization (formation of a chalcogenide layer with rich chalcogenide vacancies) and phase transformation (Co