Ultrathin Niobate Nanosheet Assembly with Au NPs and CdS QDs as a Highly Efficient Photocatalyst

Graphical An excellent 2D photocatalyst was synthesized by loading Au nanoparticles and CdS quantum dots on niobate nanosheets. This CdS/Au/HNb 3 O 8 photocatalyst not only increased the photocatalytic hydrogen evolution rate by 254 times compared with the pure niobate nanosheet, but also showed outstanding photocatalytic performance for oxidative self-coupling of benzylamine and degradation of organic dyes. Niobate nanosheets have aroused widespread interest in recent years for their prospects in catalysis. The exploration of 2D niobate catalysis with stable and efficient properties is still the focus in chemistry and materials science. Herein, the successful fabrication of 2D CdS/Au/HNb 3 O 8 catalyst is demonstrated which revealed efficient photocatalytic properties in H 2 evolution, oxidative self-coupling of amines to imines, and degradation of dyes. Especially the assembled architecture can give a rate of 5.85 mmol ⋅ g −1 ⋅ h −1 of photocatalytic H 2 evolution, an ∼254-fold enhancement, compared with bare HNb 3 O 8 nanosheets under identical conditions. In accordance with density functional theory (DFT) and X-ray adsorption fine structure (XAFS) analyses, the vast improvements are benefited from efficient migration and separation of charge carriers. Besides, the surface plasma resonance (SPR) effect of Au NPs enhances the light harvesting capacity and boosts the generation of hot electrons, efficiently improving the visible-light absorption.