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)/CeO2 nanorods heterojunction was designed and fabricated by a facile two-step method. The optimum photocatalytic H2 evolution activity for CeO2-based composites with 3 at. % CdS QDs (101.12 μ mol h–1 g–1) was 45 times as high as that of pure CeO2 nanorods (2.25 μ mol h–1 g–1) under light irradiation. Meanwhile, the photocurrent response intensity increased 17.75 times higher than pure CeO2 nanorods. Furthermore, the 0D/1D CdS QDs/CeO2 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 CeO2 nanorods to form the 0D/1D heterojunctions CdS QDs/CeO2 nanocomposites. What's more, the remarkably increased photocatalytic performance of CdS QDs/CeO2 composites was mainly attributed to the Z-scheme between CdS QDs and CeO2 nanorods, which was confirmed by the PL (photoluminescence) method. Therefore, the proposed system is highly promising for large scale photocatalytic hydrogen evolution.