Efficient decomposition of organic compounds and reaction mechanism with BiOI photocatalyst under visible light irradiation
Efficient decomposition of organic compounds and reaction mechanism with BiOI photocatalyst under visible light irradiation
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可见光照射下BiOI光催化剂高效分解有机化合物及反应机理
DOI：
10.1016/j.molcata.2010.11.005
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发表时间：
2011-01-04
影响因子：
--
通讯作者：
Li, Zhongjun
中科院分区：
文献类型：
--
作者：
Li, Yongyu;Wang, Jianshe;Li, Zhongjun
采用沉淀过滤法和水热法制备了BiOI光催化剂。在可见光照射下，所制备的BiOI对广泛应用的模型污染物橙子（MO）和苯酚具有高效的光催化降解活性。即使在紧凑型荧光灯的照射下，获得的BiOI也表现出很高的光催化活性。通过加入叔丁醇（t-BuOH）、I-、溴酸根和苯醌（BQ）等清除剂，考察了活性物种HO中心点、H（Vb）（+）和O-2（-中心点）阴离子的存在，探讨了其可能的光降解机理。结果表明，MO分子的光降解主要是由于h（vb）（+）通过直接空穴氧化过程的作用和生成的O-2（-中心点）自由基的氧化作用。溶解氧在光催化反应中起着重要的作用，它可以捕获光生电子，减少h（vb）（+）和e（cb）（-）的复合，同时也是主氧化剂O-2（-中心点）的前体。羟基自由基对MO的分解作用不大。(C)2010爱思唯尔有限公司版权所有。
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 center dot, h(vb)(+), or O-2(-center dot) 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 h(vb)(+) via direct hole oxidation process and the oxidation action of the generated O-2(-center dot) radicals. Dissolved oxygen play an important role in photocatalytic reaction, which could trap the photogenerated electrons to reduce the recombination of h(vb)(+) and e(cb)(-) and also function as a precursor of main oxidant O-2(-center dot). Hydroxyl radical was verified to be inappreciable for the decomposition of MO. (C) 2010 Elsevier B.V. All rights reserved.