Chongfei Yu,Pengyan Yang,Luna Tie,Siyu Yang,Shuying Dong,Jingyu Sun,Jianhui Sun
Herein, we demonstrate the design and fabrication of β-Bi 2 O 3 @ Bi 2 S 3 hollow microspheres with sheet-like hierarchical nanostructures targeting an advanced visible-light-responsive photocatalytic system. In comparison with pure Bi 2 S 3 and β-Bi 2 O 3 , the as-obtained β-Bi 2 O 3 @Bi 2 S 3 heterojunction photocatalyst exhibits a markedly enhanced sunlight photocatalytic activity towards the photo-degradation of rhodamine B. Following, the property of the β-Bi 2 O 3 @Bi 2 S 3 on the Cr 6+ photocatalytic reduction was then evaluated. Operating conditions such as β-Bi 2 O 3 @Bi 2 S 3 mass, tartaric acid concentration, and initial Cr 6+ concentration were analyzed. The results showed that a suitable reduction condition was selected as, β-Bi 2 O 3 @Bi 2 S 3 dosage 25 mg, initial concentration 20 mg·L −1 and molar ratio of Cr 6+ /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-Bi 2 O 3 @Bi 2 S 3 for oxidation of RhB and reduction of Cr 6+ 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.
Yangyang Zhang,Yiping Guo,Bijun Fang,Yujie Chen,Huanan Duan,Hua Li,Hezhou Liu
BiO 2 CH 3 nanoplate, a new organometallic crystal, with octagonal morphology is successfully prepared using methanol solvothermal method and further employed as template to fabricate porous β-Bi 2 O 3 octagonal nanoplates with a thickness of less than 50 nm. Then a series of hierarchical octagonal haystack-like β-Bi 2 O 3 /Bi 2 S 3 hybrids with large heterointerface and small bandgaps (1.36–1.44 eV) are constructed. It is found that, different from many regular photocatalysts that suffer from shrink of photocatalytic efficiency, the photoactivities of all β-Bi 2 O 3 /Bi 2 S 3 heterostructures are continuously enhanced with growing test cycles, owing to the formation of Bi 2 O 3− x S x solid solution, in which the built-in electric filed induced by lattice distortion can brings about higher e − /h + separation efficiency. The gradually increasing photocatalytic activity can reach to an up limit in about 5 photocatalytic cycles and maintain at this level. β-Bi 2 O 3 /Bi 2 S 3 heterostructure loaded with 20 mol% of Bi 2 S 3 is demonstrated to be the best photocatalyst and capable of fully decomposing Rh B in 30 min. Our work provides deep insights into the nature of the inversed photocatalytic behavior and facilitates the advanced design of photocatalysts with unabated photoactivities.