Abstract
Photocatalytic Z or S scheme merits higher redox potentials and faster charge separation. However, heterostructure photocatalysts with band gaps of bulk materials often have a type I band structure leading to poor photocatalytic activity. In view of this, we report simultaneous tuning of band gaps of Cu2O and TiO2, where quantum dot Cu2O nanoparticles were formed on doped TiO2 with Ti3+. The reduced size of Cu2O made its conduction band more negative, whereas the introduction of Ti3+ made the absorption edge red shift to the visible light region. The as-formed heterostructure enabled an S-Scheme mechanism with remarkable activity and stability for visible light photodegradation of 4-chlorophenol (4-CP). The as-obtained photocatalysts' activity demonstrated ca. 510-fold increase as compared to individual ones and a mechanical blend. The as-obtained photocatalysts maintained over 80 % for 5 cycles and 2 months exposure to O-2 did not decrease the degradation rate. ESR characterization and scavenger experiments proved the S-Scheme mechanism.

Keywords Plus：JUNCTIONNANOSTRUCTURESPERFORMANCECOMPOSITESCUBESCUO

Published in CHEMISTRY-A EUROPEAN JOURNAL；10.1002/chem.202102120，SEP 2021