Construction of an all-organic Z-scheme heterostructure based on 2D PDINH aggregates modified TCPP aggregates by co-assembly with enhanced photocatalytic performance

Supramolecular structures based on orderly aggregated metal-free porphyrins (TCPP) are visible-light-driven photocatalysts. But these photocatalysts possess disadvantages of poor activity and low recycling which limit their practical applications. To improve the activity and deficiencies of TCPP aggregates as photocatalysts, TCPP was combined with organic semiconductor perylene-3,4,9,10-tetracarboxylic diimide (PDINH) aggregates to construct pure organic heterojunctions (TCPP/PDINH) through the co-assembly method in this paper. Through several characterizations, it was concluded that a close contact interface formed through intermolecular pi-pi stacking and hydrogen bond interactions by the co-assembly method. The photocatalytic activity for the degradation of phenol by TCPP/PDINH was enhanced compared with that of the single aggregate, and the mechanism analysis showed that the matched energy band positions of the two aggregates and the close contact interfaces promoted the formation of a Z-scheme structure, which accelerated the charge carrier separation efficiency. In addition, the existence of two-dimensional PDINH aggregates as a support basement also improved the stability of TCPP aggregates and made them heterogeneous, which enhanced their operation and recycling.