Low-Work Function Metals Boost Selective and Fast Scission of Methanol C-H Bonds

Photocatalytic production of chemicals and fuels with H2evolution has raised broad interest due to the carbon emission-free feature. In this context, selective and fast scission of methanol C-H bonds for coproduction of H2and ethylene glycol(EG) over metal-semiconductor composites remains to be achieved. Here, we demonstrate that indium nanoparticles (InNPs) with a low work function (<4.3 eV) increase the selectivity and activity of ZnIn2S4for the scission of methanol C-H bonds. By accepting electrons from In NPs, ZnIn2S4with enrichedelectrons tends to activate the C-H bond instead of the O-Hbond. Besides, a relatively strong built-infield is formed betweenIn NPs and the support, which facilitates photogenerated electrontransfer to In NPs for H2evolution. Consequently, 84% selectivityof EG is obtained, and the apparent quantum yields (365 nm) of EG and H2reach 15.6 and 27.0%, respectively. This concept ofmethanol C-H bond scission boosted by low-work function metal is also proved by immobilizing In, Cd, and Bi to ZnS, resulting inup to 89% selectivity of EG.

Automated summary

This study demonstrates that indium nanoparticles can enhance the selectivity and activity of ZnIn2S4 for the scission of methanol C-H bonds, resulting in high selectivity and relatively high production rate of EG by facilitating photogenerated electron transfer and enriching the electrons.