Photothermal effect and continuous hot electrons injection synergistically induced enhanced molecular oxygen activation for efficient selective oxidation of benzyl alcohol over plasmonic W18O49/ZnIn2S4 photocatalyst

Abstract

The molecular oxygen activation (MOA) process tends to be the rate-limiting step for photocatalytic selective organic transformation such as aromatic alcohol oxidation. Herein, using the plasmonic 0D/2D W18O49/ZnIn2S4 (WOZ) heterojunctions as a model system, we firstly shed light on the ultra-efficient MOA origin of the synergism of photothermal effect and continuous hot electrons injection through both experimental and DFT calculations. This synergistic action not only enhances the generation rate of •O2¯ and reduces the activation energy barrier, but also significantly increases the adsorption of the O2 and activates it more easily, thus achieving efficient photocatalytic selective oxidation of benzyl alcohol to benzaldehyde. Meanwhile, the charge separation and transfer processes involved in O2 activation can be further optimized with the Z-scheme transfer route. This work would provide an exciting opportunity to construct more active photothermal catalysts with ultra-high efficiency of MOA for a wide variety of organic transformations with solar energy.