A Hierarchical Z-Scheme CdS-WO3 Photocatalyst with Enhanced CO2 Reduction Activity.
The development of an artificial photosynthetic system is a promising strategy to convert solar energy into chemical fuels. Here, a direct Z-scheme CdS-WO(3) photocatalyst without an electron mediator is fabricated by imitating natural photosynthesis of green plants. Photocatalytic activities of as-prepared samples are evaluated on the basis of photocatalytic CO(2) reduction to form CH(4) under visible light irradiation. These Z-scheme-heterostructured samples show a higher photocatalytic CO(2) reduction than single-phase photocatalysts. An optimized CdS-WO(3) heterostructure sample exhibits the highest CH(4) production rate of 1.02 μmol h(-1) g(-1) with 5 mol% CdS content, which exceeds the rates observed in single-phase WO(3) and CdS samples for approximately 100 and ten times under the same reaction condition, respectively. The enhanced photocatalytic activity could be attributed to the formation of a hierarchical direct Z-scheme CdS-WO(3) photocatalyst, resulting in an efficient spatial separation of photo-induced electron-hole pairs. Reduction and oxidation catalytic centers are maintained in two different regions to minimize undesirable back reactions of the photocatalytic products. The introduction of CdS can enhance CO(2) molecule adsorption, thereby accelerating photocatalytic CO(2) reduction to CH(4). This study provides novel insights into the design and fabrication of high-performance artificial Z-scheme photocatalysts to perform photocatalytic CO(2) reduction.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China.
Jian
J
Jin
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China.|Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
Jiaguo
J
Yu
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China.
Daipeng
D
Guo
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China.
Can
C
Cui
Department of Science and Environmental Studies and Center for Education in Environmental Sustainability, The Hong Kong Institute of Education, Tai Po, N. T. Hong Kong, P. R. China.
Wingkei
W
Ho
CdS; WO3 hollow spheres; Z-scheme photocatalysts; hierarchical; photocatalytic CO2 reduction