Synergistic Atomic‐Vacancy Engineering in S‐Scheme Heterojunction for Selective H ₂ O ₂ Photosynthesis

Solar‐driven H 2 O 2 production presents a sustainable alternative to the energy‐intensive anthraquinone process, yet remains limited by inefficient charge transfer and poor selectivity. Herein, a synergistic strategy combining the atomic defect engineering and interfacial microenvironment modulation is established, which involves the in‐situ mechanical growth of β‐ketoenamine‐linked covalent organic framework (TpBTD‐COF) onto Zn single‐atom‐anchored sulfur‐vacancy (S v )‐rich Sb 2 S 3 nanorods (Zn‐S v /Sb 2 S 3 @TpBTD) to overcome the above limitations. The optimal Zn‐S v /Sb 2 S 3 @TpBTD‐3 photocatalyst achieves a remarkable non‐sacrificial H 2 O 2 production rate of 2692 µmol g −1 h −1 with 90% selectivity in pure water, significantly outperforming most single‐atom photocatalysts. Advanced characterizations and theoretical calculations indicate that the S v ‐synergistic unsaturated Zn atomic sites as electron mediator under the internal electric field of S‐scheme heterojunction optimizes the interfacial electron transfer and promotes O 2 adsorption, significantly improving activity and selectivity for H 2 O 2 photosynthesis. This work offers an innovative perspective on the synergistic integration of defect engineering, single‐atom catalysis, and heterojunction design for modulating the interfacial charge dynamics, enabling scalable solar‐to‐chemical energy conversion applications.