TiO₂/ZnS 纳米复合材料存在下亚甲基蓝的光催化脱色

Photocatalytic decolorization of methylene blue in the presence of TiO2/ZnS nanocomposites.

作者信息

Franco A, Neves M C, Carrott M M L Ribeiro, Mendonça M H, Pereira M I, Monteiro O C

机构信息

CCMM and Department of Chemistry and Biochemistry, University of Lisbon, Campo Grande, Ed. C8, 1749-016 Lisboa, Portugal.

出版信息

J Hazard Mater. 2009 Jan 15;161(1):545-50. doi: 10.1016/j.jhazmat.2008.03.133. Epub 2008 Apr 6.

DOI:10.1016/j.jhazmat.2008.03.133

PMID:18495340

Abstract

The synthesis of distinct nanocrystalline TiO2 capped ZnS samples was carried out using a chemical deposition method. The materials characterization showed that the presence of ZnS onto TiO2 surface results in a red shift of the material band edge when compared with the initial semiconductor. The photocatalytic activity of the prepared nanocomposites was tested on the decolorization of methylene blue (MB) aqueous solutions. The dye photodecolorization process was studied considering the influence of experimental parameters such as catalyst concentration, TiO2/ZnS ratio, pH and methylene blue adsorption rate. The material with the best catalytic activity towards the methylene blue photodecolorization was the TiO2 doped with 0.2% of ZnS. The complete photodecolorization of a 20ppm methylene blue solution, at natural pH was achieved in less than 20min, nearly 70min faster than the TiO2 photoassisted process.

摘要

采用化学沉积法合成了不同的纳米晶TiO₂包覆ZnS样品。材料表征表明，与初始半导体相比，TiO₂表面存在ZnS会导致材料带边发生红移。在亚甲基蓝（MB）水溶液的脱色实验中测试了所制备纳米复合材料的光催化活性。考虑了催化剂浓度、TiO₂/ZnS比例、pH值和亚甲基蓝吸附率等实验参数对染料光脱色过程的影响。对亚甲基蓝光脱色催化活性最佳的材料是掺杂0.2% ZnS的TiO₂。在自然pH值下，20ppm亚甲基蓝溶液在不到20分钟内实现了完全光脱色，比TiO₂光辅助过程快近70分钟。