Boosting photocatalytic reduction over perylene-C3N5 driven by constructing donor-acceptor structure

As a promising N-rich carbon nitride photocatalyst, the suboptimal carrier separation capability represents a significant obstacle to C₃N₅ practical application. Herein, this work presents a constructing donor-acceptor structure (D-A) strategy for incorporating the aromatic molecule Perylene 3,4,9,10-tetracarboxylic acid (PTA) into the backbone of C₃N₅ (PTA-C₃N₅). The incorporation of PTA can facilitate the delocalization of π electrons, which enables the effective participation of photogenerated electrons in the reaction, thereby enhancing the photocatalytic capacity of the material. Moreover, the formation of the D-A structure also alters the band structure, and facilitates the migration of charge carriers. As a result, the synthesized PTA-C₃N₅ exhibits a markedly elevated efficiency for the photocatalytic reduction of Cr(VI), with a rate constant (k) of 15.65×10^-3 min^-1, which is approximately twice that of the original C₃N₅. Furthermore, the addition of PTA resulted in a notable enhancement in the crystallinity of the catalyst, effectively ameliorate the defects and suppressed the complexation of photogenerated carriers. This work presents a processing strategy for carbon nitride structural adjustment, which introduces a new paradigm for the design of organic materials at the D-A interface with the objective of achieving enhanced photocatalytic capabilities.