Preparation of TiO2/Sponge Composite for Photocatalytic Degradation of 2,4,6-Trichlorophenol

Photocatalysis has emerged as a promising approach for treating environmental pollution. In this study, TiO 2 /sponge composites with good photocatalytic activity in visible light were prepared via a simple and efficient low-temperature process and applied to the degradation of 2,4,6-trichlorophenol (2,4,6-TCP) present in papermaking wastewater. The process conditions for preparing TiO 2 /sponge composites were optimized by varying the TiO 2 dosage, cellulose dosage, and surfactant concentration. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) results showed that TiO 2 successfully adhered to the sponge surface and that the composites achieved a good recycling effect. Degradation occurred under visible light, and a degradation rate of 81% for 2,4,6-TCP with initial concentration of 20 mg/L was achieved in 4 h. The fragments were analyzed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS), which revealed the formation of 2-hydroxyvaleric acid (2-HVA) as a degradation product; a possible degradation mechanism is proposed to interpret these findings. Visible-light photocatalysis shows high potential for the rapid and environmentally friendly destruction of organic pollutants in papermaking wastewater.