Twin boundary defect engineering in Au cocatalyst to promote alcohol splitting for coproduction of H2 and fine chemicals.

[Display omitted] The microstructure of Au metal cocatalyst has been shown to significantly influence its optical and electronic properties. However, the impact of Au defect engineering on photocatalytic activity remains underexplored. In this study, we synthesize different Au-TiO 2 composites by in-situ hybridizing face-centered cubic (F-Au) and twin boundary defect Au (T -Au) nanoparticles (NPs) onto the surface of TiO 2. We find that T -Au NPs with twin defects serve as highly efficient cocatalysts for converting alcohols into their corresponding aldehydes while also generating H 2. The optimized T -Au/TiO 2 composite yields an H 2 evolution rate of 6850 µmol h−1 g−1 and a BAD formation rate of 6830 µmol h−1 g−1, about 38 times higher than that of blank TiO 2. Compared to F-Au/TiO 2 , the T -Au/TiO 2 composite enhances charge separation, extends the lifetime of electrons, and provides more active sites for H 2 reduction. The twin defect also improves alcohol reactant adsorption, boosting overall photocatalytic performance. This research paves the way for more studies on defect engineering in metal cocatalysts for enhanced catalytic activities in organic synthesis and H 2 evolution. [ABSTRACT FROM AUTHOR]