Coproduction of hydrogen and lactic acid from glucose photocatalysis on band-engineered Zn1-xCdxS homojunction
Heng Zhao, Chaofan Li, Xue Yong, Pawan Kumar, Bruna Palma, Zhi‐Yi Hu, Gustaaf Van Tendeloo, Samira Siahrostami, Steve Larter, Dewen Zheng, Shanyu Wang, Zhangxin Chen, Golam Kibria, Jinguang Hu
Abstract
Photocatalytic transformation of biomass into value-added chemicals coupled with co-production of hydrogen provides an explicit route to trap sunlight into the chemical bonds. Here, we demonstrate a rational design of Zn1-xCdxS solid solution homojunction photocatalyst with a pseudo-periodic cubic zinc blende (ZB) and hexagonal wurtzite (WZ) structure for efficient glucose conversion to simultaneously produce hydrogen and lactic acid. The optimized Zn0.6Cd0.4S catalyst consists of a twinning superlattice, has a tuned bandgap, and displays excellent efficiency with respect to hydrogen generation (690 ± 27.6 μmol·h−1·gcat.−1), glucose conversion (~90%), and lactic acid selectivity (~87%) without any co-catalyst under visible light irradiation. The periodic WZ/ZB phase in twinning superlattice facilitates better charge separation, while superoxide radical (⋅O2-) and photogenerated holes drive the glucose transformation and water oxidation reactions, respectively. This work demonstrates that rational photocatalyst design could realize an efficient and concomitant production of hydrogen and value-added chemicals from glucose photocatalysis.