Influence of Halogen Doping on g-C3N4 for Photocatalytic Degradation of RhB

Photocatalytic degradation of pollutants is considered as a promising strategy to ease the global energy and environmental issues. In this paper, g-C3N4 materials doped with halogens were prepared by a simple thermal polymerization method and effects of halogen doping on degradation of RhB by g-C3N4 under visible light were systematically investigated, and the influence of g-C3N4 doped with different I content on degradation of RhB were also studied. The results showed that g-C3N4 doped with chlorine/iodine ions showed superior behavior for degradation of RhB compared with pure g-C3N4. The absorption edge of g-C3N4 doped with Cl/I ions shifted slightly toward the long-wave range. The results of the EIS and photocurrent tests for all samples revealed that the ICN catalyst had the lowest electrical resistance, leading to a significantly accelerated interfacial charge transfer rate to the electron acceptor, as well as effectively separated electrons and holes. The degradation experiment showed that the degradation efficiency of RhB with 5% ICN content could reach nearly 100% in 90 min. This work provides a simple yet effective method to modify g-C3N4 materials by doping with halogens to degrade RhB and this work is also helpful for further studying the mechanism based on doping for modification of catalysts and further research are being planned.