付有,古建,李茹玉,李文森,冷宛聪,匡鑫,马健,华英杰,王崇太*.CdSQDs/TiO2复合材料的制备及光催化性能[J].海南师范大学学报自科版,2020,33(3):255-260 |
CdSQDs/TiO2复合材料的制备及光催化性能 |
Preparation of CdS Quantum Dot Composite Photocatalytic MaterialCdSQDs / TiO2 and Its Degradation of Organic Pollutant RhB |
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DOI:10.12051/j.issn.1674-4942.2020.03.003 |
中文关键词: 有机污染物降解 二氧化钛 溶胶-凝胶法 量子点 光催化 |
英文关键词: degradation of organic pollutants titanium dioxide sol-gel method quantum dot photocatalysis |
基金项目:海南省社会发展专项(ZDYF2017083) |
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中文摘要: |
采用溶胶-凝胶法制备了一种CdS 量子点(QDs)与TiO2的复合材料(CdSQDs/TiO2)。该
材料具有较高的光催化活性和稳定性,在250 W 金卤灯(波长> 420 nm)照射下催化降解初始浓度
为10 μmol/L 的模型污染物罗丹明B(RhB),反应120 min,RhB 的降解率达到97%;反应240 min,
RhB 的TOC 去除率约34%;经过8 次循环使用,其光催化活性几乎没有损失。5,5-二甲基1-吡咯
啉N-氧化物(DMPO)捕获自由基的电子顺磁共振(ESR)实验证明,光催化过程产生了·O2
-和·OH
自由基,正是这些活性氧物质导致了RhB 的降解。根据实验事实提出的光催化反应机理表明,
CdSQDs 和TiO2之间产生了协同作用,促进了光电子的转移,降低了光电子与空穴复合的几率,从而
提高了光催化效率。 |
英文摘要: |
In this paper, a composite material composed of CdS quantum dot and TiO2 was prepared using sol-gel meth⁃
od. This material presents a high photocatalytic activity and stability. The degradation rate of RhB with an initial concentra⁃
tion of 10 μmol/L reached 97% at 120 min and the TOC removal was about 34% at 240 min under the irradiation of 250 W
metal halide lamp(λ>420 nm). After being cyclically reused for 8 times, almost no loss of the photocatalytic activity was ob⁃
tained. Electron spin resonance (ESR) experiment in which radicals were captured by 5,5-dimethyl-1-pyrroline N-oxide
(DMPO) proved that ·O2- and ·OH radicals were generated in the photocatalytic process, which led to the degradation of
RhB. A photocatalysis mechanism proposed in terms of experimental facts indicates that the synergistic effect between Cd⁃
SQDs and TiO2 facilitates the photogenerated electrons transfer and reduces the probability of the recombination of photo⁃
electrons and holes , thus the photocatalytic efficiency is improved. |
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