Boosting Hydrogenation of Graphene Quantum Dot-Modified Photocatalysts: Specific Functionalized Modulation at Active Sites

Engineering the electronic structure of active sites on photocatalyst surfaces can help realize high activity through strong interactions with reactants. However, unimpeded photo-charge transport is highly limited by a mismatch between pristine catalysts and reactants because of the lack of group-specific modulated synthesis of semiconductor-based catalysts. In this study, hollow TiO2/poly(diallyl-dimethylammonium chloride)/graphene quantum dot (GQD) hybrid catalysts were established through a noncovalent self-assembly surface modification strategy. The multilayered nanostructure of the composite catalysts ensures a synchronous charge transfer chain for directional photo-charge migration. Furthermore, GQDs with different hydroxyl contents were deposited onto the hybrids for tuning the catalyst-reactant interfacial coupling. Transient-state surface photovoltage analysis revealed that group-specific absorption and activation dominated the interfacial photo-charge transport dynamics between the catalysts and reactants. The proposed strategy may facilitate the maneuvering of the active sites of semiconductor-based catalysts for improving specific hydrogenation reactions.