Construction of ternary heterojunction CuS-CdS/TiO2 nanobelts for photocatalytic degradation of gaseous toluene

Abstract

The ternary heterojunction CuS-CdS/TiO2 nanobelts (CuS-CdS/TiO2 NBs) were successfully prepared. The CuS-CdS/TiO2 NBs photocatalyst was used for the decomposition of gaseous toluene under simulated solar light irradiation. Results showed that the construction of ternary heterojunction CuS-CdS/TiO2 NBs improved the photocatalytic activity. The coupling of CuS-CdS heterojunction with TiO2 NBs promoted the absorbance in visible light region. CdS and CuS were brought in contact as a cascade structure, forming the stepwise energy level structure, which leads to the increased separation and transfer of photogenerated electrons and holes. The results demonstrated that photocatalytic degradation rate increased with increasing photocatalyst area from 16 to 40 cm2. With an increase in initial concentration, the decomposition of toluene showed a tendency to increase, however, there was an optimum concentration at 4215 ppm. The optimal flow rate and reaction temperature were around 1.5 L/min and 40 °C, respectively. After illumination of 100 min the conversion of toluene was about 88.12% and the produced CO2 was about 9353 ppm, corresponding to a mineralization ratio of 31.70%. It is hoped that our work could provide a valuable evidence for directing the rationally fabrication of ternary nanojunctions photocatalysts for environment cleanup.