Direct Z-scheme TiO2/CdS hierarchical photocatalyst for enhanced photocatalytic H2-production activity

Abstract Photocatalytic H 2 evolution, which utilizes solar energy via water splitting, is a promising route to deal with concerns about energy and environment. Herein, a direct Z-scheme TiO 2 /CdS binary hierarchical photocatalyst was fabricated via a successive ionic layer adsorption and reaction (SILAR) technique, and photocatalytic H 2 production was measured afterwards. The as-prepared TiO 2 /CdS hybrid photocatalyst exhibited noticeably promoted photocatalytic H 2 -production activity of 51.4 μmol h −1 . The enhancement of photocatalytic activity was ascribed to the hierarchical structure, as well as the efficient charge separation and migration from TiO 2 nanosheets to CdS nanoparticles (NPs) at their tight contact interfaces. Moreover, the direct Z-scheme photocatalytic reaction mechanism was demonstrated to elucidate the improved photocatalytic performance of TiO 2 /CdS composite photocatalyst. The photoluminescence (PL) analysis of hydroxyl radicals were conducted to provide clues for the direct Z-scheme mechanism. This work provides a facile route for the construction of redox mediator-free Z-scheme photocatalytic system for photocatalytic water splitting.