Adsorption-photocatalytic degradation and kinetic of sodium isobutyl xanthate using the nitrogen and cerium co-doping TiO2-coated activated carbon

Abstract

At present, the excessive use of sodium isobutyl xanthate (SIBX) in mineral processing has caused serious environmental problems, drawing ever-growing concern in China. A nitrogen and cerium co-doped TiO2-coated activated carbon (Ce/N–TiO2@AC) heterojunction were prepared through the sol-gel method to address these problems. The photocatalyst was characterized using XRD, TEM, SEM-EDS, PL, UV–Vis, XPS and a series of photoelectrochemical techniques. The results show that Ce/N–TiO2@AC photocatalyst possess a stable anatase phase, narrow band gap energy (2.24–2.61 eV) and high charge transport process. The photocatalytic activity of the photocatalyst was evaluated based on photodegradation kinetic studies of SIBX in aqueous solution, and it is found that it followed the Langmuir-Hinshelwood model very well. The Ce/N–TiO2@AC photocatalyst with 2% Ce appears to be the highest removal rate with 96.3% of SIBX and an apparent rate constant of 78.4 × 10−3 min−1. The reusability experiment for its potential applications was studied, and the removal rate of SIBX reached 95.8% after the fifth cycle. Besides, the proposed mechanism and degradation routes of SIBX were systematically studied, and certificate the concentration of SO2-4 ions in the final water sample was 95.9 mg/L, which was basically consistent with the theoretical value.