Preparation of g-C3N5 composites for butyl xanthate photocatalytic degradation

Abstract

The nitrogen-rich graphite-phase carbon nitride (g-C3N5) supported TiO2 photocatalyst (Ti-CN) was prepared using TiO2 and 3-amino 1, 2, 4-triazole as raw materials for butyl xanthate residual (SBX) removal from mineral processing wastewater. The crystal, morphology, specific surface area and optical properties of the Ti-CN were characterized by XRD, TEM, UV–vis DRS, BET and PL. These results showed that TiO2 particles were uniformly dispersed on g-C3N5 nanosheets, and the heterojunction was formed. The formation of heterojunction improved its response to visible light, and promoted the separation of photoelectron-hole, contributing to improving its photocatalytic activity. The influence of catalyst dosage, initial SBX concentration and pH value of the SBX solution on SBX photocatalytic degradation removal was investigated. The Box-Behnken design of the response surface was used to optimize the process conditions to obtain the optimal experiment conditions with the pH of 7.04, catalyst dosage of 50.2 mg and SBX concentration of 56.6 mg/L. The SBX photocatalytic degradation removal of Ti-CN is 98.15 %, which is close to the predicted value of 97.75 % at the optimal experiment conditions. Meanwhile, the SBX degradation removal of Ti-CN still had 90.21 % after five cycles, indicating that Ti-CN has good stability. These results indicate that Ti-CN can be used as the promising photocatalyst for SBX from mineral processing wastewater.