催化学报

催化学报 ›› 2012, Vol. 33 ›› Issue (7): 1209-1216.DOI: 10.3724/SP.J.1088.2012.20320

• 研究论文 • 上一篇    下一篇

Ag@AgBr 光催化剂的制备及其可见光催化降解亚甲基蓝反应性能

聂龙辉*, 黄征青, 徐洪涛, 张旺喜, 杨柏蕊, 方磊, 李帅华   

  1. 湖北工业大学化学与环境工程学院, 湖北武汉 430068
  • 收稿日期:2012-03-12 修回日期:2012-04-06 出版日期:2012-06-21 发布日期:2012-06-21

Synthesis of Ag@AgBr Photocatalyst and Its Performance for Degradation of Methylene Blue under Visible-Light Irridiation

NIE Longhui*, HUANG Zhengqing, XU Hongtao, ZHANG Wangxi, YANG Borui, FANG Lei, LI Shuaihua   

  1. School of Chemical and Environmental Engineering, Hubei University of Technology, Wuhan 430068, Hubei, China
  • Received:2012-03-12 Revised:2012-04-06 Online:2012-06-21 Published:2012-06-21

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1525

被引次数

77

摘要： 采用沉积-沉淀及光还原法制备了 Ag@AgBr 等离子体光催化剂, 利用 X 射线衍射、扫描电镜和紫外-可见漫反射光谱对其进行了表征, 并考察了该等离子体光催化剂在可见光 (l > 420 nm) 下的催化性能, 探讨了催化剂用量、pH 值、亚甲基蓝初始浓度、H2O2 添加量、循环使用及捕获剂对 Ag@AgBr 催化性能的影响. 结果表明, 当亚甲基蓝的初始浓度为 10 mg/L, 催化剂用量为 1 g/L, pH = 9.8 时, 光照 12 min 后, 亚甲基蓝的降解率高达 96%, 且样品经 5 次循环使用后活性基本保持不变; 而少量 H2O2 的添加对光催化活性影响不大, 过量的 H2O2 会降低光催化活性; 乙二胺四乙酸捕获空穴后比异丙醇捕获•OH 后的光催化活性降得更低. 同时, 对 Ag@AgBr 等离子体光催化剂可见光降解亚甲基蓝的催化机理进行了分析.

关键词: 银, 溴化银, 等离子体共振, 光催化, 可见光活性, 亚甲基蓝

Abstract: Ag@AgBr plasmon photocatalyst was prepared by the deposition-precipitation and photo-reduction method. The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy, and UV-Vis diffuse spectroscopy. The photocatalytic activity and stability of the prepared samples were evaluated by the degradation of methylene blue (MB) under the visible light (l > 420 nm) irradiation. Several parameters, such as catalyst concentration, pH value, initial MB concentration, H2O2 content, recycling runs, and scavengers, were examined. The results show that the photocatalytic activity of Ag@AgBr reached 96% in MB aqueous solution (10 mg/L) containing 1 g/L catalyst at pH = 9.8 under visible-light irradiation, and it almost kept unchanged after five-cycle photocatalytic test. The degradation efficiency of MB had little variation in the presence of a small amount of H2O2 but reduced in the presence of excessive H2O2. MB photodegradation was greatly suppressed by ethylenediaminetetraacetic acid while slightly decreased by isopropanol. The photocatalytic mechanism for MB degradation by Ag/AgBr under visible light irradiation was also presented.

Key words: silver, silver bromide, plasmon resonance, photocatalysis, visible-light activity, methylene blue