Solar-boosted electrocatalytic oxygen evolution via catalytic site remodelling of CoCr layered double hydroxide

Abstract Water splitting, as a powerful technology for converting renewable energy into hydrogen energy, suffers from the kinetically sluggish oxygen evolution reaction (OER). Herein, encouraged by the structural characteristic of layered double hydroxide (LDH), CoCr LDH was proposed, for the first time, to verify the photoelectric synergy towards catalyzing OER. Under AM 1.5 irradiation, the optimal CoCr LDH presents a 1.35∼1.5-fold enhanced OER intrinsic activity and a faster charge transfer, thus achieving a decreased overpotential of 28 mV at 100 mA cm−2 in 1.0 M KOH. Meanwhile, the H2 amount produced at the cathode also increases 1.8 times. The synergistic enhancement in the highly active Co3+ sites and the charge transfer, both triggered by the photo-generated carriers on CoCr LDH, is mainly responsible for such a remarkably improved activity. This proof-of-concept study provides a reasonable and scalable platform towards engineering the self-consistent catalysts for the photoelectric synergy system.