Facile layer-by-layer self-assembly of 2D perovskite niobate and layered double hydroxide nanosheets for enhanced photocatalytic oxygen generation

Photocatalytic O₂-generation reaction is recognized as a crucial step in water splitting and has drawn great attention of researchers. In this work, a hetero-layered composite photocatalyst was successfully prepared by a facile self-assembly method based on electrostatic interaction between oppositely charged Zn/Cr-layered double hydroxide (Zn/Cr-LDH) and lead niobate nanosheets. The layer-by-layer stacking of Zn/Cr-LDH and HPb₂Nb₃O₁₀ nanosheets was beneficial for rapid migration of photo-induced charge carriers inside the photocatalyst because of large contact area. In the meantime, Zn/Cr-LDH and HPb₂Nb₃O₁₀ components exhibited suitable energy-band alignment, which led to efficient separation of photo-induced charge carriers. The composite photocatalyst showed enhanced photocatalytic O₂-generation activity under visible-light irradiation without loading cocatalyst. Briefly, this work expanded the applications of AB₂Nb₃O₁₀-based materials in photocatalytic energy conversion and proved that constructing composites based on electrostatic self-assembly of complementary 2D materials is a promising strategy for development of more efficient photocatalysts.