Self-assembled perylene diimide decorated g-C3N4 heterojunction catalyst with strong interfacial charge transfer through π-π interaction for efficient boosted photocatalytic degradation of tetracycline

Perylene diimide (PDI) organic material and its derivatives as photocatalysts possesses excellent charge separation efficiency and are renowned as among the top n-type organic semiconductors capable of absorbing visible light owing to their narrow band gap (∼1.69 eV). Heterojunction photocatalysts with efficient electron transfer and excellent photocatalytic performance are of great significance for the degradation of organic compounds in the environment. In this work, a series of heterojunction catalysts (CNPDI) with robust interfacial charge transfer via π-π interaction were prepared using g-C 3 N 4 and different mass ratio of the self-assembled PDI as precursors, subsequently utilized as efficient visible-light-driven photocatalysts for the degradation of organic tetracycline. SEM and TEM results indicated that porous CN was completely wrapped around PDI nanorod structure formed by strong π-π interactions. In the presence of activating potassium peroxymonosulfate (PMS) substances, the kinetic rate constant of the CNPDI photocatalytic system clocked in at 0.026 min −1 , marking 2.36 fold increase compared to the original CN (0.011 min −1 ). The bolstered degradation performance was attributed to the built-in potential formed by the self-assembled PDI and CN, promoting the separation of electron-hole pairs and redistribution of charge density in the interface region. This work presents a useful insight into the crafting of PDI-based heterojunction photocatalysts for degradation environmental pharmaceutical pollutants.