Benzene Ring Engineering of Graphitic Carbon Nitride for Enhanced Photocatalytic Dye Degradation and Hydrogen Production from Water Splitting
Yongbo Fan, Lin Lei, Jingshen Cao, Weijia Wang, Huiqing Fan
Abstract
The photocatalytic activity of graphitic carbon nitride (g‐C 3 N 4 ) strongly depends on its electronic structure. To design the photocatalysts with efficient charge separation and transfer property, here a benzene ring‐doped g‐C 3 N 4 via one‐pot thermal polycondensation of dicyandiamide and 2,4‐diaminobenzenesulfonic acid is reported. The carbon‐rich benzene ring is embedded into g‐C 3 N 4 , which enables the asymmetric modification of the heptazine units in g‐C 3 N 4 and the extension of the π‐conjugate system without altering its long‐range order structure significantly. Such molecular structure optimization effectively improves the visible light harvesting and charge carriers separation ability. A high photocatalytic hydrogen evolution rate and dye degradation performance is achieved under visible light irradiation (λ > 420 nm), which is about 8.4 and 4.4‐fold higher than that of pristine g‐C 3 N 4 , respectively. The reason for enhanced photocatalytic performance is ascribed to a favorable optical property, suppressed charge carrier recombination, and efficient charge transfer processes. This work provides a green and economical method to functionalize g‐C 3 N 4 using low‐content organic carbon molecule for efficient energy conversion‐related applications.