Efficient Visible Light-Driven Photocatalytic Degradation of Pentachlorophenol with Bi2O3/TiO2–xBx
Efficient Visible Light-Driven Photocatalytic Degradation of Pentachlorophenol with Bi2O3/TiO2–xBx
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DOI：
10.1021/jp305432g
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发表时间：
2012-08
影响因子：
3.7
通讯作者：
Ke Su;Zhihui Ai;Lizhi Zhang
中科院分区：
文献类型：
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作者：
Ke Su;Zhihui Ai;Lizhi Zhang
以五氯苯酚为目标物，制备了一种B掺杂和Bi 2 O3偶联的新型TiO 2光催化剂（Bi 2 O3/TiO 2-xBx），并在可见光（λ > 420 nm）照射下降解五氯苯酚。所得到的Bi 2 O3/TiO 2-xBx样品表现出比仅掺杂B或Bi 2 O3耦合或纯TiO 2的对应物高得多的光催化性能。这是因为B掺杂可以导致更多的可见光吸收，从而产生更多的光生电子-空穴对，而Bi 2 O3耦合可以促进光生载流子的分离和转移，从而抑制它们的复合。发现Bi 2 O3/TiO 2-xBx光催化降解五氯苯酚的动力学机制主要是光生空穴和·O2-的作用，而不是以前报道的·OH的作用。这是因为B 2 p轨道和O 2 p轨道的杂化使Bi 2 O3/TiO 2-xBx光催化剂的VB边比纯TiO 2的高，从而降低了光生空穴的氧化能力，阻断了光生空穴的氧化途径。
In this study, a new TiO2-based photocatalyst with both B doping and Bi2O3 coupling (Bi2O3/TiO2–xBx) was synthesized to degrade pentachlorophenol under visible light (λ > 420 nm) irradiation. The resulting Bi2O3/TiO2–xBx sample exhibited much higher photocatalytic performance than the counterparts with only B doping or Bi2O3 coupling or pure TiO2. This is because B doping could result in more visible light absorption to produce more photogenerated electron–hole pairs, while Bi2O3 coupling could favor the separation and transfer of photoinduced charge carriers to inhibit their recombination. We interestingly found that the visible light-driven degradation of pentachlorophenol was mainly attributed to photogenerated holes and ·O2– other than ·OH as reported previously because the hybridization of B 2p orbital and O 2p orbital could elevate the VB edge of Bi2O3/TiO2–xBx as compared to that of pure TiO2 and thus lower the oxidation ability of photogenerated holes, blocking the pathway of photogenerated holes ...