Target preparation of multicomponent composites Au@CdS/g-C3N4 as efficient visible light photocatalysts with the assistance of biomolecules

Highlights: • Au@CdS/g-C₃N₄ composites were prepared through a novel biomolecules assisted hydrothermal route. • Au@CdS core-shell structure is formed in composites. • The composites exhibit high visible light photocatalytic activity and stability. • The enhanced photocatalytic properties are ascribed to the efficient charges separation. - Abstract: In this work, we aimed to develop a novel method for the target preparation of multicomponent composites Au@CdS/g-C₃N₄ towards high visible light photocatalytic activity with the assistance of L-cysteine biomolecules. Through the interaction of L-cysteine biomolecules with Au nanoparticles and g-C₃N₄ bulks, CdS layer were in-situ precipitated on the surface of Au nanoparticles to form core-shell structure Au@CdS and Z-scheme structure Au@CdS-g-C₃N₄ with good interface bonding in composites. By taking advantage of this feature, the highest reaction rate constant of 8%Au@CdS/g-C₃N₄ for methyl orange dye and phenol degradation was 3.08- and 1.48-folds higher than pure g-C₃N₄ bulks, which was ascribed to the strong interaction between different substances for efficient charges transferring and separation as evidenced by the studies of X-ray photoelectron spectroscopy, steady-state and transient photoluminescence spectroscopy. This work highlights the utilization of biomolecules for the target preparation of composites and its application on environmental remediation.