Freeze-dried PVP-Ag+ precursors to novel AgBr/AgCl-Ag hybrid nanocrystals for visible-light-driven photodegradation of organic pollutants
Freeze-dried PVP-Ag+ precursors to novel AgBr/AgCl-Ag hybrid nanocrystals for visible-light-driven photodegradation of organic pollutants
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冻干 PVP-Ag 前体制备新型 AgBr/AgCl-Ag 杂化纳米晶体，用于可见光驱动的有机污染物光降解
DOI：
10.1016/j.spmi.2015.01.004
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发表时间：
2015-04-01
影响因子：
3.1
通讯作者：
Shao, Guosheng
中科院分区：
文献类型：
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作者：
Chen, Deliang;Chen, Qianqian;Shao, Guosheng
以冷冻干燥的PVP-Ag+杂化物为银源，通过液固分步反应合成了不同摩尔br /Ag比（R-Br/Ag = 0、1/3、1/2、2/3、1）和不同光还原时间（0-20 min）的AgBr/AgCl-Ag纳米晶体，并进行光还原反应。得到的AgBr/AgCl-Ag-7.5（1:2）纳米晶体呈球形，粒径范围为58 +/- 15 nm。在人工可见光（λ >= 420 nm, 100 mW cm(-2)）下，通过光降解有机染料、4-氯酚和异丙醇，评价了AgBr/AgCl-Ag纳米晶体的光催化性能。对于罗丹明B的分解，AgBr/AgCl-Ag-7.5（1:2）纳米晶的光降解速率为0.87 min(-1)，比TiO2 （P25）的光降解速率（约0.0054 min(-1)）高159倍，而AgCl-Ag和AgBr- ag纳米晶的光降解速率分别为0.35 min（-1）和0.45 min（-1）。在由AgBr、AgCl和Ag组成的三元体系中，光生电子空穴对的有效分离是提高光催化性能的关键。(C) 2015 Elsevier Ltd.版权所有。
AgBr/AgCl-Ag nanocrystals with various molar Br-to-Ag ratios (R-Br/Ag = 0, 1/3, 1/2, 2/3, 1) and different photoreduction times (0-20 min) were synthesized via stepwise liquid-solid reactions using the freeze-dried PVP-Ag+ hybrid as the Ag source, followed by a photoreduction reaction. The AgBr/AgCl-Ag-7.5(1:2) nanocrystals obtained take on a spherical morphology with a particle-size range of 58 +/- 15 nm. The photocatalytic performance of AgBr/AgCl-Ag nanocrystals was evaluated by photodegrading organic dyes, 4-chlorophenol and isopropanol under artificial visible light (lambda >= 420 nm, 100 mW cm(-2)). For the decomposition of rhodamine B, the AgBr/AgCl-Ag-7.5(1:2) nanocrystals has a photodegradation rate of similar to 0.87 min(-1), similar to 159 times higher than that (similar to 0.0054 min(-1)) of TiO2 (P25), whereas the AgCl-Ag and AgBr-Ag nanocrystals have photodegradation rates of 0.35 min(-1) and 0.45 min(-1), respectively. The efficient separation of photogenerated electron-hole pairs in the ternary system consisting of AgBr, AgCl and Ag species plays a key role in the enhancement of photocatalytic performance. (C) 2015 Elsevier Ltd. All rights reserved.