Novel ionic liquid modified carbon nitride fabricated by in situ pyrolysis of 1-butyl-3-methylimidazolium cyanamide to improve electronic structure for efficiently degradation of bisphenol A

Abstract For this study, ionic liquid-modified carbon nitride (hm-CN) was one-step synthesized by 1-butyl-3-methylimidazolium cyanamide and carbon nitride (g-C3N4). After the addition of ionic liquids, the structural change of hm-CN increases the separation of photogenerated electron holes and improves the photocatalytic performance. The colorless pollutant bisphenol A (BPA) is degraded as the target pollutant under the visible light irradiation. The catalytic performance of g-C3N4 modified by ionic liquid is better than pure g-C3N4. The best performance is 30hm-CN, which degrades 95% of the pollutants in 3 hours. Its degradation performance is 4.5 times that of pure g-C3N4 and the degradation performance is still excellent after three cycles. According to electron spin resonance (ESR) and trapping experiments, h+ and •O2− play a key role in the photocatalytic degradation process. In addition, we conducted a series of condition experiments to perform degradation under different catalyst concentrations, different ions and different pH to fully understand the impact of external interference on the catalyst. At the same time, the sample also has good activity in degrading other pollutants (Rhodamine B, Methylene blue, Tetracycline, Ciprofloxacin). This study simply designed a method to synthesize ionic liquid modified g-C3N4 for improving photocatalytic performance, and provided a new idea for the research of carbon nitride modification at the same time.