Interfacial Proton-Relay Microenvironment Enables Self-Driven Singlet Oxygen Generation under Neutral Conditions

The energy-free activation of ambient molecular oxygen (O₂) to singlet oxygen (¹O₂) under neutral conditions is highly desirable for green oxidation chemistry, yet remains fundamentally limited by sluggish proton-coupled *OOH formation and desorption. Here, we engineer an interfacial proton-relay microenvironment between MoS₂ and CuCl that enables self-driven O₂-to-¹O₂ conversion without external energy inputs. Electron-deficient sulfur sites act as a proton reservoir by forming S-H_ads species, facilitating directional proton migration through Cu-S-Mo channels to activate adsorbed O₂ on electron-rich Cu sites. This coupled electron-proton relay accelerates *OOH hydrogenation while maintaining moderate *O2/*OOH binding, effectively suppressing O─O bond cleavage and favoring a 1O2-dominated pathway. As a result, the system achieves quantitative pollutant removal and sustained operation for over 16 h in pilot-scale membrane filtration. This interfacial design is broadly applicable to transition metal sulfides, offering a general strategy to overcome proton-transfer limitations and advance autonomous catalytic platforms for sustainable oxidation and environmental remediation.