Imide modification coupling with NH2-MIL-53(Fe) boosts the photocatalytic performance of graphitic carbon nitride for efficient water remediation

Graphite carbon nitride (g-C3N4) is a significant non-metal photocatalyst, but still challenging for photocatalytic degradation of pollutants because of its poor visible light utilization, easy recombination of photo-generated carriers and low surface reactive reaction sites. In this paper, perylene diimide (PDI), an electron-deficient building block for constructing n-type organic semiconductors, was introduced into the framework of g-C3N4 (PDI-g-C3N4) to build polymer with donor-acceptor structure for energy band amelioration, achieving the most expanded visible light response up to date. Besides, a large dihedral angle (90 degrees) induced by PDI moiety in PDI-g-C3N4 changes the molecular aggregation behavior according to calculations, which is advantageous to increase surface area for the reactive site exposure. The most promising functional photocatalyst PDI-g-C3N4/MIL is constructed by in-situ generation of NH2-MIL-53 (Fe) on the surface of PDI-g-C3N4 to further facilitate the separation and transfer of interfacial photo-induced carriers. Through a finely adjusting ratio of PDI-g-C3N4 in heterojunction, the target material of PDI-g-C3N4/MIL exhibits superior activity for the photodegradation of organic pollutants in the presence of H2O2 and visible light illumination, providing potential direction in practical application for wastewater treatment. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

Perylene diimide (PDI) was introduced into the framework of g-C3N4 to build a polymer with a donor-acceptor structure, optimizing the energy band structure and increasing visible light responsiveness. This modification also led to an increased exposure of reactive sites, resulting in superior performance in the photodegradation of organic pollutants in wastewater treatment.