CdS/ZnO复合光催化剂降解亚甲基蓝的研究

摘要

利用水热法合成具有层级片状结构的ZnO纳米片,再利用原位生长法得到不同CdS复合比的CdS/ZnO复合光催化剂.采用X射线粉末衍射(XRD)、紫外-可见漫反射吸收光谱(UV-Vis)等手段对所制备的光催化剂进行了表征,并考察了CdS/ZnO在可见光下光催化降解亚甲基蓝溶液的催化性能.研究表明,经CdS修饰后,其光催化性能明显提高.当亚甲基蓝初始浓度为5 mg·L-1,催化剂用量为2 g·L-1时,光反应240 min后,亚甲基蓝的降解率高达96％.同时,对CdS/ZnO复合光催化剂可见光降解亚甲基蓝的催化机理进行了分析.%Hierarchical ZnO composed of nanosheets structures were fabricated through a hydrothermal method. Afterwards,CdS loaded ZnO(CdS/ ZnO)were obtained by in-situ growth method. The as-prepared samples were characterized by X-ray diffraction (XRD),UV-Vis diffuse reflectance spectra(DRS). The photocatalytic performance of ZnO/ CdS photocatalysts were evaluated by the photodegradation of methylene blue(MB)under the visible light(λ>420nm)irradiation. The results indicate that after modifica-tion with CdS,the composite photocatalysts exhibit higher photocatalytic activity compared with pure ZnO. The photocatalytic activity of 5％ CdS/ ZnO reached 96％ in MB aqueous solution(5 mg·L-1 )containing 2g·L-1 catalyst under visible-light irradiation. Final-ly the photocatalytic mechanism for MB degradation by CdS/ ZnO under visible light irradiation was also presented.