Boosted Photocatalytic Oxidation of Toluene into Benzaldehyde on CdIn2S4‑CdS: Synergetic Effect of Compact Heterojunction and S‑Vacancy

The enhancement of electron-and-hole separation efficiency and facile generation of reactive oxygen species are significant factors for performance improvement of photocatalysts in selective toluene photocatalytic oxidation. Heterojunction and defect construction have been regarded as valid methods to boost photocatalytic activity of semiconductors. Herein, the CdIn2S4-CdS composite with compact heterojunctions and defect-induced sulfur vacancies was fabricated by a one-step hydrothermal process. The sheet-to-sheet heterojunctions and the abundant sulfur vacancies facilitate separation and migration of photoinduced charge carriers. Benefited from the compositional and structural synergy, the prepared CdIn2S4-CdS-140 composite boosted photocatalytic oxidation activity for toluene conversion into benzaldehyde (remarkable toluene conversion of 80.3% and benzaldehyde selectivity of 99% in 6 h) under visible light irradiation. It is noteworthy that the composite can perform well when pure O2 was replaced with air.