S-scheme enhanced photocatalysis on titanium oxide clusters functionalized with soluble perylene diimides

Fabricating S-scheme photocatalysts to optimize their ability of using sunlight has gained great attention in environmental remediation. Herein, we designed a soluble hybrid, titanium oxide cluster-perylene diimide-polyhedral oligomeric silsesquioxane (TOC-PDI-POSS). Through pi-pi stacking interaction with the most commonly applied graphitic carbon nitride (g-C3N4), a new S-scheme heterostructure was successfully constructed. The combination of the near full visible light responsive TOC-PDI-POSS and g-C3N4 enhanced the utilization of sunlight to achieve highly efficient charge-carrier separation. More importantly, the photo-Fenton reaction can be achieved without an extra oxidant. Owing to the enhanced oxidation capacity of holes, the obtained TOC-PDI-POSS/g-C3N4 heterostructure displayed efficient photocatalytic degradation for phenol under an air atmosphere and the reaction rate constant reaches 5.6 h(-1) in five cycles under simulated sunlight.