Selective oxidation of benzyl alcohol into benzaldehyde over semiconductors under visible light: The case of Bi12O17Cl2 nanobelts
Selective oxidation of benzyl alcohol into benzaldehyde over semiconductors under visible light: The case of Bi12O17Cl2 nanobelts
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DOI：
10.1016/j.apcatb.2013.05.047
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发表时间：
2013-10
影响因子：
22.1
通讯作者：
Xiaoyi Xiao;Jing Jiang;Lizhi Zhang
中科院分区：
文献类型：
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作者：
Xiaoyi Xiao;Jing Jiang;Lizhi Zhang
在本研究中，我们提出了几个标准的半导体光催化剂适用于可见光驱动的选择性氧化BA到BAD通过使用几个文献报道的光催化剂（P25，g-C3 N4，In（OH）xSy，Bi 3 O 4 Br，BiOBr和Cu 2 O）在可见光下氧化BA，证明了苯甲醇的光催化氧化选择性与其价带的位置密切相关半导体和Bi_（12）O_（17）Cl_2纳米带可以在可见光下通过直接空穴氧化将苯甲醇高效选择性氧化为苯甲醛。虽然分子氧的存在和超氧自由基的产生对于苯甲醇的选择性氧化是重要的，但分子氧的确切作用仅仅是在Bi 12 O 17 Cl 2氧化过程中捕获光生电子产生超氧自由基，它可以抑制光生载流子的复合，但可能不直接参与醇的氧化。发现分子氧在Bi_（12）O_（17）Cl_2氧化过程中所起的作用不同于以前报道的TiO_2和g-C_3 N_4的作用。该研究为醇在可见光下的选择性氧化过程中活性物种的作用和新型可见光活性光催化剂的设计提供了新的物理见解。
In this study we propose several criteria for semiconductor photocatalysts suitable for visible light driven selective oxidation of BA to BAD by employing several literature-reported photocatalysts (P25, g-C3N4, In(OH)xSy, Bi3O4Br, BiOBr and Cu2O) to oxidize BA under visible light, and then demonstrate that the selectivity of photocatalytic oxidation of benzyl alcohol is highly depended on the position of valence band of semiconductors and Bi12O17Cl2nanobelts could efficiently and selectively oxidize benzyl alcohol into benzaldehyde under visible light via direct hole oxidation. Although the presence of molecular oxygen and the generation of superoxide radicals are important for the selective oxidation of benzyl alcohol, the exact role of molecular oxygen is merely to trap photogenerated electrons to produce superoxide radicals during Bi12O17Cl2photocatalysis, which could inhibit the recombination of photogenerated charge carries, but might not be involved in the alcohol oxidation directly. The role of molecular oxygen during Bi12O17Cl2photocatalysis was found to be different from those of TiO2and g-C3N4previously reported. This study provides new physical insights for the roles of active species during selective oxidation of alcohol under visible light and the design of novel visible light active photocatalysts for selective oxidation of alcohol.