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

Summary 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 twinned superlattice (TSL), 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 wurtzite/zinc-blende 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 rational photocatalyst design could realize an efficient and concomitant production of hydrogen and value-added chemicals from glucose photocatalysis.