Higher dye degradation using a visible-light photocatalyst made of mesoporous graphitic carbon nitride prepared with the Tween-40 surfactant

Water pollution by organic pollutants such as textile dyes is a serious problem that could be solved by advanced photocatalytic semiconductors. Here we synthesized a visible-light photocatalyst made of mesoporous graphitic carbon nitride using the surfactant Tween-40, and we compared the surfactant performance in degrading rhodamine B with graphitic carbon nitride prepared by conventional methods. The toxicity of the photocatalyst was evaluated using bioassays with Allium Cepa. Results show that 93.0% of the rhodamine B was degraded by the new catalyst after 60 min under visible-light irradiation, whereas bulk graphitic carbon nitride and mesoporous graphitic carbon nitride with Pluronic F127 degraded only 30.5 and 86.0% of rhodamine B, respectively. We also found no ecotoxicity of the new catalyst. Higher degradation performance of the photocatalyst is explained by synergistic effect of nitrogen vacancies combined with the higher number of structural defects and more active sites, and by a better separation and transport of photogenerated charges of the synthesized mesopore catalyst, thus inducing a better response under visible light.