Coproduction of hydrogen and lactic acid from glucose photocatalysis on band-engineered Zn1-xCdxS homojunction

Heng Zhao; Chao-Fan Li; Xue Yong; Pawan Kumar; Bruna Palma; Zhi-Yi Hu; Gustaaf Van Tendeloo; Samira Siahrostami; Stephen Larter; Dewen Zheng; Shanyu Wang; Zhangxin Chen; Md Golam Kibria; Jinguang Hu

doi:10.1016/j.isci.2021.102109

Coproduction of hydrogen and lactic acid from glucose photocatalysis on band-engineered Zn_1-xCd_xS homojunction

iScience. 2021 Jan 28;24(2):102109. doi: 10.1016/j.isci.2021.102109. eCollection 2021 Feb 19.

Authors

Heng Zhao¹, Chao-Fan Li^{2

3}, Xue Yong⁴, Pawan Kumar¹, Bruna Palma¹, Zhi-Yi Hu^{2

3}, Gustaaf Van Tendeloo^{3

5}, Samira Siahrostami⁴, Stephen Larter⁶, Dewen Zheng⁷, Shanyu Wang⁷, Zhangxin Chen¹, Md Golam Kibria¹, Jinguang Hu¹

Affiliations

¹ Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada.
² State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China.
³ Nanostructure Research Centre (NRC), Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China.
⁴ Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
⁵ Electron Microscopy for Materials Science (EMAT), University of Antwerp, 171Groenenborgerlaan, B-2020 Antwerp, Belgium.
⁶ Department of Geosciences, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada.
⁷ Research Institute of Petroleum Exploration and Development (RIPED), CNPC, Beijing 100083, China.

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 Zn_1-xCd_xS 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 Zn_0.6Cd_0.4S 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·g_cat. ^-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.

Keywords: Catalysis; Chemistry; Engineering; Materials Science.