Construction of Z-Scheme System for Enhanced Photocatalytic H2 Evolution Based on CdS Quantum Dots/CeO2 Nanorods Heterojunction

Photocatalytic hydrogen evolution from water splitting is a promising approach in energy conversion and storage. Here, the 0D/1D CdS quantum dots (QDs)/CeO 2 nanorods heterojunction was designed and fabricated by a facile two-step method. The optimum photocatalytic H 2 evolution activity for CeO 2 -based composites with 3 at. % CdS QDs (101.12 μ mol h –1 g –1 ) was 45 times as high as that of pure CeO 2 nanorods (2.25 μ mol h –1 g –1 ) under light irradiation. Meanwhile, the photocurrent response intensity increased 17.75 times higher than pure CeO 2 nanorods. Furthermore, the 0D/1D CdS QDs/CeO 2 heterojunctions exhibited enhanced photocatalytic stability for long lifetime (60 h). The reasons that dramatically enhanced photocatalytic performance could be the improved light harvesting, enhanced photoresponse and stronger electronic conductivity while the CdS QDs was loaded in CeO 2 nanorods to form the 0 D /1D heterojunctions CdS QDs/CeO 2 nanocomposites. What’s more, the remarkably increased photocatalytic performance of CdS QDs/CeO 2 composites was mainly attributed to the Z-scheme between CdS QDs and CeO 2 nanorods, which was confirmed by the PL (photoluminescence) method. Therefore, the proposed system is highly promising for large scale photocatalytic hydrogen evolution.