One-pot fabrication of β-Bi2O3@Bi2S3 hierarchical hollow spheres with advanced sunlight photocatalytic RhB oxidation and Cr(VI) reduction activities

Herein, we demonstrate the design and fabrication of β-Bi2O3@Bi2S3 hollow microspheres with sheet-like hierarchical nanostructures targeting an advanced visible-light-responsive photocatalytic system. In comparison with pure Bi2S3 and β-Bi2O3, the as-obtained β-Bi2O3@Bi2S3 heterojunction photocatalyst exhibits a markedly enhanced sunlight photocatalytic activity towards the photo-degradation of rhodamine B. Following, the property of the β-Bi2O3@Bi2S3 on the Cr6+ photocatalytic reduction was then evaluated. Operating conditions such as β-Bi2O3@Bi2S3 mass, tartaric acid concentration, and initial Cr6+ concentration were analyzed. The results showed that a suitable reduction condition was selected as, β-Bi2O3@Bi2S3 dosage 25 mg, initial concentration 20 mg·L−1 and molar ratio of Cr6+/tartaric acid 1:20. The outstanding photocatalytic performances of the hybrid photocatalyst are mainly attributed to the reduced recombination rates of photo-generated electrons/holes, enhanced light harvesting, increased active sites as well as the improved photo/chemical stability. Moreover, the photocatalytic mechanism of β-Bi2O3@Bi2S3 for oxidation of RhB and reduction of Cr6+ was investigated in detail. The enhanced photocatalytic activity and excellent chemical stability render the thus-fabricated heterostructure a promising candidate to remediate aquatic contaminants and meet the demands of future photocatalytic materials.