Synthesis of ternary CdS-G-LTO hybrids with enhanced photocatalytic performance for natural food pigment industrial wastewater

Abstract

In this work, a series of CdS-G-LTO composites were fabricated and characterized using multiple methods, to determine their performance for degrading natural food pigments in industrial wastewater. The optimal composite for the degradation of MO was CdS-G-LTO-2 (20 wt% CdS), with degradation rate of 109 times and 50 times higher than that of LTO thin film and G-LTO. The photocatalytic performance of these composites with regard to gardenia yellow pigment and real wastewater was also investigated. The removal efficiency of chorma and TOC for gardenia yellow reached 83% and 75% respectively after 40 min; while for the wastewater, the removal efficiency of COD and TOC was 62% and 74.4% after 6 h. The enhanced photocatalytic activity was ascribed to the high separation and transfer rate of photo-excited charge carriers. The O2– radicals (as the main species) and h+ both participated in the photocatalytic degradation reaction of gardenia yellow.