Synthesis of Immobilized CdS/TiO_2 Nanofiber Heterostructure Photocatalyst for Efficient Degradation of Toluene

摘要

The immobilized CdS/TiO2 nanofiber (CdS/TiO2 NF) heterostructure photocatalyst was fabricated via anodic oxidation and cyclic impregnation method. The microstructure of CdS/TiO2 NF was characterized by SEM and TEM. The components of CdS/TiO2 NF were identified by EDX, XPS, and Raman. The optical properties of CdS/TiO2 NF were characterized by UV-vis DRS and PL. Results showed that CdS was loaded on the surface of TiO2 NF in the form of particles with a diameter of about 10-80 nm. The Cd and S elements were detected on the surface of catalyst. CdS/TiO2 NF improved the absorption performance in the ultraviolet and visible light regions and reduced the recombination of photogenerated electron-hole pairs. The performance of CdS/TiO2 NF on degrading toluene was investigated. Results showed that the deposition of CdS enhanced the photocatalytic activity of TiO2 NF. The toluene concentration, catalyst dosage, and flow rate had marked impact on the photocatalytic degradation efficiency of toluene. In this reaction system, the degradation ratio was 80.71% when the toluene concentration was 13 mg center dot L-1, the photocatalyst area was 32 cm(2), the flow rate was 3 L center dot min(-1), and the illumination time was 100 min. The mineralization ratio after photocatalytic reaction for 100 min was about 45.02%. The immobilized CdS/TiO2 NF photocatalyst is easy to be recycled, which can reduce the energy and material cost. This work not only highlights the intrinsical role of CdS materials in the enhanced photocatalytic performance of TiO2 NF but also provides significant guidance on fabricating immobilized CdS/TiO2 NF photocatalyst applied in environment remediation.