LAUSR

Hydroxyl radical (•OH) stemming from dissolved oxygen (O2) via photocatalysis is very attractive, but its poor selectivity and generation efficiency greatly limit its application. Herein, a kind of tungsten single site co-coordinated with O and S atoms (WO3S1) is established on ZnIn2S4 (W-ZIS). The strong interactions in WO3S1 shift the d-band center toward the Fermi level, enhancing the adsorption of O2. These interactions improve the accumulation of photo-generated electrons on WO3S1, facilitating the dissociation of O─O bonds in crucial intermediates and promoting the selective conversion from O2 into •OH. This brings a state-of-the-art selectivity (40.2%) and generation efficiency (1668.90 mmol. g-1. L-1. h-1) of •OH production. Experimental results and theoretical simulations have elucidated that O2 can be reduced by d-orbitals single electron (↑, _, _, _, _, _) of WO3S1 transfer to 2p-orbital O─O pi anti-bonding (π*: px and py), initially activating O2. Additionally, WO3S1 sites facilitate the cleavage of H2O, optimizing proton adsorption through W─O orbital coupling in WO3S1 and promoting the transformation of oxygen-containing intermediates. More importantly, d-orbitals single electron can fill O─O π* bond in •OOH intermediate, weakening the covalency of the O─O bond, mitigating the formation of H2O2 and shortening the pathway for •OH generation.).