Visible light photocatalytic degradation of dyes by β-Bi2O3/graphene nanocomposites

• Published in: Journal of alloys and compounds 2015-11, Vol.649, p.872-877
• Main Authors: Chen, Xuefu, Dai, Jianfeng, Shi, Gaofeng, Li, Lan, Wang, Guoying, Yang, Hua
• Format: Article
• Language: English
• Subjects: Hydroxyl radicals; Photocatalysis; β-Bi2O3/GR composites
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2015.05.096

β-Bi2O3 nanoparticles with an average grain size of 100nm were synthesized by a polyacrylamide sol–gel method. Their bandgap energy is obtained by ultraviolet–visible diffuse reflectance spectroscopy is 2.37eV. β-Bi2O3/GR composites were fabricated by mixing β-Bi2O3 nanoparticles and graphene into absolute ethanol solution followed by thermal drying. A transmission electron microscopy observation shows that β-Bi2O3 nanoparticles are well assembled onto GR sheets. The photocatalytic activity of prepared samples was evaluated by degrading methylene blue under the irradiation of visible light. Compared to bare β-Bi2O3 nanoparticles, β-Bi2O3/GR composites exhibit significantly enhanced photocatalytic activity. Detected by the photoluminescence technique that of using terephthalic acid as a probe molecule, hydroxyl (OH) radicals are found to be produced on the irradiated β-Bi2O3/GR composites. Based on the experimental results, OH radicals are suggested to be the major active species which is responsible for the degradation reaction. •The β-Bi2O3/graphene composites were prepared by an ultrasound assisted method.•The visible light activity of β-Bi2O3/graphene was evaluated by degrading methylene blue.•The β-Bi2O3/graphene composites exhibit significantly enhanced photocatalytic activity.•The OH radicals are suggested to be the major active species.