Electronic configuration inversion in CdIn₂S₄ for efficient photocatalytic hydrogen peroxide generation coupled with...

Vacancies engineering has sparked a huge interest in enhancing photocatalytic activity, but monovacancy simultaneously conducts as either electron or hole acceptor and redox reaction, worsening charge transfer and catalytic performance. Here, the concept of electronic inversion has been proposed through the simultaneous introduction of surface oxygen and S vacancies in CdIn₂S₄ (OS_v-CIS). Consequently, under mild conditions, the well-designed OS_v-CIS-200 demonstrated a strong rate of N-benzylidenebenzylamine production (2972.07 µmol g^-1 h^-1) coupled with Hydrogen peroxide (H₂O₂) synthesis (2362.33 µmol g^-1 h^-1) (PIH), which is 12.4 times higher than that of CdIn₂S₄. Density functional theory (DFT) simulation and characterization studies demonstrate that oxygen is introduced into the lattice on the surface of the material, reversing the charge distribution of the S vacancy and enhancing the polarity of the total charge distribution. It not only provides a huge built-in electric field (BEF) for guiding the orientation of the charge transfer, but also acts as a long-distance active site to accelerate reaction and prevent H₂O₂ decomposition. Our work offers a straightforward connection between the atomic defect and intrinsic properties for designing high-efficiency materials.