CdS-decorated surface-coarsened TiO₂ nanobelts with enhanced visible-light photocatalytic performances

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 TiO₂ nanobelts were fabricated by in-situ-deposited CdS on the surface-coarsened TiO₂ 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 m² g⁻¹ and the band gap of 2.22 eV. Owing to the synergic effect between CdS and surface-coarsened TiO₂ 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 H₂ 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 TiO₂ nanobelts. The possible photodegradation mechanism was provided by investigating the active species.