A Hydrogen‐Deficient Nickel–Cobalt Double Hydroxide for Photocatalytic Overall Water Splitting
Min Wang, Jiaqi Wang, Cong Xi, Chuanqi Cheng, Chengqin Zou, Rui Zhang, Ya‐Meng Xie, Zhonglu Guo, Chengchun Tang, Cunku Dong, Yongjun Chen, Xi‐Wen Du
Abstract
Abstract Developing highly efficient and low‐cost photocatalysts for overall water splitting has long been a pursuit for converting solar power into clean hydrogen energy. Herein, we demonstrate that a nonstoichiometric nickel–cobalt double hydroxide can achieve overall water splitting by itself upon solar light irradiation, avoiding the consumption of noble‐metal co‐catalysts. We employed an intensive laser to ablate a NiCo alloy target immersed in alkaline solution, and produced so‐called L‐NiCo nanosheets with a nonstoichiometric composition and O 2− /Co 3+ ions exposed on the surface. The nonstoichiometric composition broadens the band gap, while O 2− and Co 3+ ions boost hydrogen and oxygen evolution, respectively. As such, the photocatalyst achieves a H 2 evolution rate of 1.7 μmol h −1 under AM 1.5G sunlight irradiation and an apparent quantum yield (AQE) of 1.38 % at 380 nm.