CdS-decorated surface-coarsened TiO_2 nanobelts with enhanced visible-light photocatalytic performances

摘要

Photodegradation of pollutants and photocatalytic hydrogen evolution of water splitting have been regarded as effective paths to solve the global environmental pollution and energy shortage. Herein, CdS-decorated surface-coarsened TiO_2 nanobelts were fabricated by in-situ-deposited CdS on the surface-coarsened TiO_2 nanobelts prepared by hydrothermal procedure followed by acid etched, and the visible-light photocatalytic performances were investigated. The as-synthesized composites presented multi-crystalline phase heterostructure with the specific surface of 64.368 m~2 g~(-1) and the band gap of 2.22 eV. Owing to the synergic effect between CdS and surface-coarsened TiO_2 nanobelts with multi-crystalline phase self-transformed heterostructure, the prepared composites showed effective separation of photogenerated carriers and excellent visible-light photocatalytic performances. Under visible-light irradiation, the degradation efficiency of methylene blue reached 99.7% with the photodegradation rate constant of 0.0231 min~(-1), and the average H_2 evolution rate was 0.6225 mmol g~(-1) h~(-1) over 6 h. The visible-light photocatalytic activities of the as-prepared composites were greatly enhanced compared to CdS and CdS-decorated TiO_2 nanobelts. The possible photodegradation mechanism was provided by investigating the active species.