Constructing Z-scheme based CoWO_4/CdS photocatalysts with enhanced dye degradation and H_2 generation performance

摘要

The artificial Z-scheme photocatalysts, simulating the natural photosynthesis, enables more efficient utilization of solar energy for sustainable fuel production. A novel direct Z-scheme CoWO4/CdS binary photocatalyst is synthesized by an in-situ hydrothermal method, and the enhanced activities of H-2 production and dye degradation are attained. The rate of H-2 production is 15.91 mmol/h/g, which is 24-fold higher than CdS. The CoWO4/CdS composites exhibited outstanding stability after five consecutive reactions. Meanwhile, the photocatalytic removal efficiencies of MG are about CdS CWC-0.8 CWC1.0 CWC-1.4 CWC-1.2. The preeminent photocatalytic property of CoWO4 /CdS composites is authenticated based on Z-scheme heterojunction. Most importantly, the enhancement mechanism is attributed to the effective isolation of photogenerated carriers and the existance of redox capabilities for CoWO4/CdS system. This work might provide novel conception for the design and construction of high-performance photocatalysts with direct Z-scheme. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.