Cascade Reaction for Efficient 1 O 2 Generation Enabled by Spatially Coupled Vacancy Pairs

ABSTRACT Singlet oxygen ( 1 O 2 ) is a powerful nonradical oxidant for water purification, particularly in complex matrices. However, its spin‐forbidden generation from triplet oxygen ( 3 O 2 ) imposes significant thermodynamic barriers. This study reports a pulsed‐laser synthesis strategy to create atomically adjacent vacancy pairs (V Ti–O ) on the surface of TiO 2 , which function as a cooperative bifunctional redox nanoreactor for the sustainable generation of 1 O 2 . The oxygen vacancy (V O ) serves as a reduction site for O 2 adsorption and activation, whereas the adjacent titanium vacancy (V Ti ), acting as an oxidation site, immediately converts superoxide (O 2 ·− ) into 1 O 2 . The V Ti–O pair shortens the migration path of O 2 ·− , inhibits quenching, and enhances the overall reaction kinetics. In an integrated fixed‐bed reactor operated under natural sunlight in a real water environment, this catalyst enables efficient pollutant degradation while maintaining aquatic biocompatibility, demonstrating its practical potential for low‐energy, efficient 1 O 2 generation and wastewater treatment in sustainable solar‐driven advanced oxidation processes.