A novel calcined Bi₂WO₆/BiVO₄ heterojunction photocatalyst with highly enhanced photocatalytic activity

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• 作者：Peng Ju ; Ping Wang ; Bin Li ; Hai Fan ; Shiyun Ai ; Dun Zhang ; Yi Wang
• 关键词：Bi2WO6 ; BiVO4 ; Heterojunction ; Photocatalysis ; Visible light
• 刊名：Chemical Engineering Journal
• 出版年：15 January, 2014
• 年：2014
• 卷：236
• 期：Complete
• 页码：430-437
• 全文大小：2192 K

文摘

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 掳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) 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.