Visible-light photocatalytic activity and mechanism of novel AgBr/BiOBr prepared by deposition-precipitation

• Published in: Chinese science bulletin 2012-08, Vol.57 (22), p.2901-2907
• Main Authors: Lin, HaiLi, Cao, Jing, Luo, BangDe, Xu, BenYan, Chen, ShiFu
• Format: Article
• Language: English
• Subjects: absorption; AgBr; Chemistry/Food Science; Diffraction; Earth Sciences; Engineering; Humanities and Social Sciences; irradiation; Life Sciences; multidisciplinary; photolysis; Physics; reflectance; scanning electron microscopy; Science; Science (multidisciplinary); spectroscopy; transmission electron microscopy; X-ray diffraction; 光催化活性; 可见光区; 扫描电子显微镜; 沉淀; 沉积; 溴化银; 透射电子显微镜
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1007/s11434-012-5260-6

A new composite photocatalyst AgBr/BiOBr was prepared by loading AgBr on a BiOBr substrate via deposition-precipitation and characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectroscopy. The as-prepared AgBr/BiOBr comprised face-centered cubic AgBr and tetragonal BiOBr particles. The average crystalline sizes of AgBr in the AgBr/BiOBr composites were less than 28.5 nm. The absorption edges of AgBr/ BiOBr in visible-light region had a red shift with increasing AgBr content. Photocatalytic degradation of methyl orange results show that the AgBr/BiOBr composites could degrade methyl orange efficiently under visible-light irradiation （λ〉420 nm）. The optimal molar percentage of AgBr was 50 mol% with corresponding maximum kapp of 0.00619 rain-1. Active · O（-,2） played a major role for methyl orange degradation while h＋ and · OH had little effect on the photocatalytic process. The enhancement of photo- catalytic activity of AgBr/BiOBr is mainly ascribed to the heterojunction effect between AgBr and BiOBr.