A novel calcined Bi2WO6/BiVO4 heterojunction photocatalyst with highly enhanced photocatalytic activity
A novel calcined Bi2WO6/BiVO4 heterojunction photocatalyst with highly enhanced photocatalytic activity
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DOI：
10.1016/j.cej.2013.10.001
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发表时间：
2014-01-15
影响因子：
15.1
通讯作者：
Wang, Yi
中科院分区：
文献类型：
--
作者：
Ju, Peng;Wang, Ping;Wang, Yi
本研究通过水热法制备了一种新型的可见光敏感焙烧Bi2WO6/BiVO4 （C-Bi2WO6/BiVO4）异质结光催化剂，该催化剂由Bi2WO6和BiVO4组成，具有良好的可见光吸收性能。实验结果表明，C-Bi2WO6/BiVO4比C-Bi2WO6、C-BiVO4和未煅烧的Bi2WO6/BiVO4具有更高的光催化活性，并且在30 min内Rhodamine B （RhB）的降解效率可达到100%。此外，经过6次循环光降解RhB后，C-Bi2WO6/BiVO4没有表现出明显的光催化活性损失，证实了其稳定性和长期的可重复使用性。通过活性物质捕获实验研究了光催化机理，发现空穴（h（+)）和羟基自由基(OH)- o -中心点）在RhB降解过程中起关键作用。此外，根据计算的能带，光催化性能的明显增强可归因于光诱导电子空穴对的有效分离。此外，煅烧提高了C-Bi2WO6/BiVO4的结晶度，结合其优异的光吸收能力进一步提高了其光催化活性。本研究为设计具有增强光催化性能的复合光催化剂提供了一种新的策略，用于水净化和其他应用。(C) 2013 Elsevier B.V.版权所有
In this study, a novel visible-light-sensitive calcined Bi2WO6/BiVO4 (C-Bi2WO6/BiVO4) heterojunction photocatalyst was synthesized via a hydrothermal process followed by the calcination at 600 degrees C. The as-prepared multilayer C-Bi2WO6/BiVO4 photocatalyst was composed of Bi2WO6 and BiVO4 with a good visible-light absorption performance. Experimental results showed that C-Bi2WO6/BiVO4 exhibited higher photocatalytic activity than C-Bi2WO6, C-BiVO4, and uncalcined Bi2WO6/BiVO4, and the degradation efficiency of Rhodamine B (RhB) could achieve 100% within 30 min. In addition, after six recycles for the photodegradation of RhB, C-Bi2WO6/BiVO4 did not exhibit significant loss of photocatalytic activity, confirming its stability and long-time reusability. The photocatalytic mechanism was studied by active species trapping experiments, revealing that the holes (h(+)) and hydroxyl radicals ((OH)-O-center dot) played key roles in RhB degradation. Moreover, on the basis of the calculated energy bands, the obviously enhanced photocatalytic performance can be attributed to the efficient separation of photoinduced electron hole pairs. In addition, the calcination improved the crystallinity of C-Bi2WO6/BiVO4, combined with the excellent photoabsorption ability further improved its photocatalytic activity. The present study provides a new strategy to design composite photocatalysts with enhanced photocatalytic performance for water purification and other applications. (C) 2013 Elsevier B.V. All rights reserved.