CdS/CeO2 heterostructures as visible-light photocatalysts for the reduction of nitro to amine organics

Highlights: • One-dimensional CdS/CeO₂ heterostructures with tunable mass loading of CdS without any surfactants were prepared. • ž The CdS/CeO₂ exhibits superior catalytic performances to the nitro reduction under visible-light illumination. • ž The enhanced mechanism was proposed to be the synergistic effect, the clean surface, and the special morphology. -- Abstract: We developed an easy-operation synthetic methodology to one-dimensional CdS/CeO₂ heterostructures, which were formed by hybriding the CeO₂ nanorods and CdS nanoparticles with varied mass loading of CdS. The heterostructures will be an ideal candidate as superior photocatalysts owing to their composite and structural features. We took the reduction of nitro organics with various substituents as probing reactions to evaluate their photocatalytic performances. As expect, the CdS/CeO₂ heterostructures exhibit significantly enhanced and composition-dependent photocatalytic activity under visible-light illumination. Based on our systematic investigations, we ascribed the significantly improved visible-light harvesting properties to the hybriding of narrow-bandgap CdS with CeO₂ and the negative potential of the conductive edge benefits for the reduction of H⁺ to active hydrogen species. More importantly, the CdS sensitization effect accelerates the interface carrier separation and transfer processes due to the formation of heterostructure. The life time of the photogenerated electrons are remarkably prolonged. Moreover, the 3-CdS/CeO₂ composites also exhibit excellent photocatalytic stability.