Effective dye degradation by an environment-friendly porous few-layered carbon nitride photocatalyst developed using sequential molecule self-assembly.

Abstract Two-dimensional (2D) g-C3N4 (CN) has garnered massive interest for photocatalytic applications owing to its excellent photon contact area, visible-light absorption, and easy transport of photogenerated charge carriers to the surface. However, bulk CN suffers from intrinsically poor charge separation, limited specific surface area, and insufficient visible-light absorption, significantly limiting its photocatalytic efficiency. Exfoliation of bulk crystals into nanosheets with few layers has proven to be an effective and widely used strategy to enhance photocatalytic performance; however, this process is quite complicated, requiring longer times and external energy. Here, a few-layered porous g-C3N4 (PCN) was synthesized using the molecular self-assembly process. This prepared PCN exposes more active sites, leading to enhanced separation of charge carriers, resulting in a higher photocatalytic activity than regular CN. PCN achieved the best photocatalytic degradation (97.46%) of Rhodamine B (RhB) dye in 1 h, which is three times higher than that by CN (32.57%) because of enhanced porosity of the photocatalyst with few layers. This enhanced degradation performance of PCN was caused by increased visible-light absorption and charge separation along with higher number exposed active sites triggered by the high porosity under visible light, which is greater than those of other metal-free photocatalysts reported thus far.