Synthesis of BiOBr/WO3 p-n heterojunctions with enhanced visible light photocatalytic activity
Synthesis of BiOBr/WO3 p-n heterojunctions with enhanced visible light photocatalytic activity
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具有增强可见光催化活性的 BiOBr/WO3 p-n 异质结的合成
DOI：
10.1039/c6ce00824k
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发表时间：
2016
期刊：
影响因子：
3.1
通讯作者：
Liu Jianshe
中科院分区：
文献类型：
--
作者：
Zhang Junlei;Zhang Lisha;Shen Xiaofeng;Xu Pengfei;Liu Jianshe
光催化技术发展的一个前提是获得具有优异活性的光催化剂。在此，我们报道了BiOBrWO3p-n异质结作为一种新型高效的可见光驱动光催化剂。采用电纺-焙烧-溶剂热法制备了BiOBr/WO_3 p-n异质结，它们都呈现出花朵状的超结构。以罗丹明B(RhB)、甲基橙(MO)和对氯苯酚(4-CP)为研究对象，考察了它们在可见光(λ>；400 nm)下的光催化活性。以RhB为目标污染物时，不同BiOBR和WO_3(1/0.5，1/1，1/2)理论摩尔比的BiOBR/WO_3 p-n异质结的光催化活性均高于纯WO_3和BiO_3。其中，摩尔比为1/1的BiOBrWO3p-n异质结表现出最高的光催化活性，甚至高于相同组份质量的两种单一光催化剂(WO3光催化剂和BiOBr光催化剂)的光催化活性。此外，当MO或4-CP作为目标污染物时，摩尔比为1/1的BiOBrWO3p-n异质结仍表现出良好的光催化性能。此外，回收实验证实了BiOBrWO3p-n异质结在光催化过程中基本稳定。BiOBrWO3p-n异质结光催化活性的提高主要归因于光生电子和空穴的有效分离。光生空穴(h+)和超氧阴离子(·O2−)是导致RhB染料在水中几乎完全矿化的主要活性物种。
A prerequisite for the development of photocatalysis techniques is to obtain photocatalysts with remarkable activity. Herein, we have reported BiOBr/WO3 p–n heterojunctions as novel and efficient visible-light-driven photocatalysts. The BiOBr/WO3 p–n heterojunctions have been prepared through an electrospinning–calcination–solvothermal method, and they all present a flower-like superstructure. The photocatalytic activities of these p–n heterojunctions are investigated by degrading rhodamine B (RhB), methyl orange (MO) and para-chlorophenol (4-CP) under visible light irradiation (λ > 400 nm), respectively. When RhB serves as the target pollutant, all BiOBr/WO3 p–n heterojunctions with different theoretical molar ratios of BiOBr and WO3 (1/0.5, 1/1, 1/2) exhibit higher photocatalytic activity than pure WO3 or BiOBr. Especially, the BiOBr/WO3 p–n heterojunction with a molar ratio of 1/1 displays the highest photocatalytic activity among all the as-synthesized catalysts, even higher than the activity from the mixture of two individual photocatalysts with the same weight of components (WO3 and BiOBr). In addition, when MO or 4-CP acts as the target pollutant, the BiOBr/WO3 p–n heterojunction with a molar ratio of 1/1 still exhibits excellent photocatalytic performance. Furthermore, the recycling experiment confirms that the BiOBr/WO3 p–n heterojunction is essentially stable during the photocatalytic process. The enhanced photocatalytic activity of the BiOBr/WO3 p–n heterojunction is predominantly attributed to the efficient separation of photogenerated electrons and holes. The photogenerated holes (h+) and superoxide radical anions (˙O2−) have been found to be the primary reactive species responsible for the nearly complete mineralization of RhB dye in water.