Hexagonal 2D NiCo-LDO supported on 0D CoWO4 to construct a p–n heterojunction for efficient photocatalytic hydrogen evolution

Abstract

Nearly hexagonal two-dimensional NiCo layered dioxide oxides (NiCo-LDO) were successfully combined with CoWO₄ to improve hydrogen production performance. Hexagonal 2D NiCo-LDO was fixed on the surface of CoWO₄ to form NiCo-LDO/CoWO₄(NCLW) with a p–n heterojunction structure. This structure contributes to the separation and transfer of photoinduced electrons (e⁻) and holes (h⁺), prolongs the carrier life, and improves the photocatalytic activity. Photocatalytic experiments showed that the hydrogen production of the p–n heterojunction NCLW under visible light irradiation for 5 h was 77.14 μmol, which was 3.4 times that of pure NiCo-LDO (22.41 μmol) and 40 times that of pure CoWO₄ (1.93 μmol). Our discovery of NCLW in the photocatalytic decomposition of aquatic hydrogen will lead to new insights for the design and development of new photocatalytic materials based on layered double oxides (LDO).