Efficient decomposition of organic compounds and reaction mechanism with BiOI photocatalyst under visible light irradiation

• Published in: Journal of molecular catalysis. A, Chemical Vol. 334; no. 1-2; pp. 116 - 122
• Main Authors: Li, Yongyu, Wang, Jianshe, Yao, Hongchang, Dang, Liyun, Li, Zhongjun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.01.2011; Elsevier
• Subjects: anions; benzoquinones; Bismuth oxyiodide; Catalysis; catalytic activity; Chemistry; dissolved oxygen; electrons; Exact sciences and technology; fluorescence; General and physical chemistry; hot water treatment; hydroxyl radicals; iodides; irradiation; lighting; methyl orange; oxidants; oxidation; phenol; photocatalysts; Photochemistry; photolysis; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); pollutants; Reaction mechanism; superoxide anion; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Visible-light-driven photocatalyst; Reaction mechanism; Visible-light-driven photocatalyst; Bismuth oxyiodide; Ternary compound; Heterogeneous catalysis; Photocatalysis; Visible radiation; Decomposition; Bismuth Iodides oxides; Organic compounds
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2010.11.005

BiOI photocatalyst with efficient visible photocatalytic activity was synthesized by a precipitation–filtration process and consequent hydrothermal treatment, and its photodegradation mechanism was studied systematically. [Display omitted] ▶ BiOI photocatalyst was synthesized successfully. ▶ BiOI exhibits excellent photocatalytic activity. ▶ Photodegradation mechanism was investigated systematically. ▶ hvb+ and O2− radicals were proven to be the main oxidants. BiOI photocatalyst was synthesized by a precipitation–filtration process and consequent hydrothermal treatment. The as-prepared BiOI exhibits efficient photocatalytic activity on the decomposition of widely used model pollutants, methyl orange (MO) and phenol, under visible light irradiation. Even under the illumination of a compact fluorescent lamp, the obtained BiOI also exhibits high photocatalytic activity. The possible photodegradation mechanism was studied by the examination of active species HO, hvb+, or O2− anions through adding scavengers such as tert-butanol (t-BuOH), I− anion, bromate anion and benzoquinone (BQ). The results show that photodegradation of MO molecules is attributed to the action of hvb+ via direct hole oxidation process and the oxidation action of the generated O2− radicals. Dissolved oxygen play an important role in photocatalytic reaction, which could trap the photogenerated electrons to reduce the recombination of hvb+ and ecb− and also function as a precursor of main oxidant O2−. Hydroxyl radical was verified to be inappreciable for the decomposition of MO.