Compressive interatomic distance stimulates photocatalytic oxygen-oxygen coupling to hydrogen peroxide.

Photocatalytic hydrogen peroxide (HO) generation is largely subject to the sluggish conversion kinetics of the superoxide radical (O) intermediate, which has relatively low reactivity and requires high energy. Here, we present a lattice-strain strategy to accelerate the conversion of O to highly active singlet oxygen(O) by optimizing the distance between two adjacent active sites, thereby stimulating HO generation via low-barrier oxygen-oxygen coupling. As the initial demonstration, the defect-induced strain in ZnInS nanosheet optimizes the distance of two adjacent Zn sites from 3.85 to 3.56 Å, resulting in that ZnInS with 0.7% compressive strain affords 3086.00 μmol g h yield of HO with sacrificial agent. This performance is attributed to the strain-induced enhancement of electron coupling between the compressed adjacent Zn sites, which promotes low-barrier oxygen-oxygen coupling to active O intermediate. This finding paves the way for atomic-scale manipulation of reactive sites, offering a promising approach for efficient HO photosynthesis.