Photoinduced Translocation-Transformation Strategy for Vacancy Re-Exposure and Synthesis of Stable Single Atoms

Single-atom catalysts have attracted considerable attention owing to their unparalleled atomic-level efficiencies and distinctive structural properties. However, traditional synthesis methods often lead to less-than-optimal catalytic performance, as single atoms may occupy and block surface vacancies beneficial for catalytic activity. Achieving single-atom dispersion while retaining or reactivating vacancies remains challenging. This paper proposes a photoinduced translocation-transformation strategy using anatase TiO₂ with high concentrations of surface oxygen vacancies as a support. Following N doping, Rh nanoparticles are loaded and subsequently disperse into single atoms through a photoinduced treatment accompanied by N translocation, ultimately restoring the oxygen vacancy concentrations to levels comparable to those of the original TiO₂. This approach enhances the photocatalytic performance, yielding a hydrogen production rate twofold higher for the single-atom catalyst Rh(SA)/N-TiO₂ than for the nanoparticle catalyst Rh(NP)/N-TiO₂. This novel method is promising in organic synthesis, CO₂ reduction, and nitrogen fixation applications.