Novel Bi2S3/TiO2 heterogeneous catalyst: Photocatalytic mechanism for decolorization of Texbrite dye and evaluation of oxygen species

Abstract

A heterogeneous Bi2S3/TiO2 composite catalyst was synthesized via a green ultrasonic-assisted method and characterized by XRD, SEM, EDX, TEM analysis. The results clearly show that the TiO2 particles were homogenously coated with Bi2S3 particles, indicating that Bi2S3 particle agglomeration was effectively inhibited after the introduction of anatase TiO2. The Texbrite BA-L (TBA) degradation rate constant for Bi2S3/TiO2 composites reached 8.27 × 10-3 min-1 under visible light, much higher than the corresponding value of 1.04 × 10-3 min-1 for TiO2. The quantities of generated hydroxyl radicals can be analyzed by DPCI degradation, which shows that under visible light irradiation, more electron-hole pairs can be generated. Finally, the possible mechanism for the generation of reactive oxygen species under visible-light irradiation was proposed as well. Our result shows the significant potential of Bi2S3-semiconductor-based TiO2 hybrid materials as catalysts under visible light for the degradation of industry dye effluent substances.