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通过水热法合成分散性良好的CdS纳米颗粒,并采用声化学法在颗粒外包覆TiO2壳层,获得的复合材料具有更好的光催化特性。讨论了水热反应温度保温时间与晶粒尺寸、结晶性之间的关系以及声化学制备过程中反应条件与陈化时间对壳层生长的影响。采用X射线衍射、透射电镜、漫反射光谱、光催化性能测试等手段表征CdS颗粒的尺寸、形貌及CdS/TiO2的结构与光催化特性。结果表明:水热过程中,提高反应温度、保温时间有利于提高产物的结晶性。声化学合成CdS/TiO2复合材料过程中,超声作用能促进核壳结构的形成。提高前驱溶液的浓度,在获得CdS/TiO2核壳结构的同时会析出TiO2纳米粒子。在降解甲基橙的实验中,CdS/TiO2材料表现出比单组分材料更好的催化性能。
The CdS nanoparticles with good dispersibility were synthesized by hydrothermal method and the TiO2 shell was coated by sonochemical method. The obtained composite has better photocatalytic properties. The relationship between the holding time of hydrothermal reaction and the grain size and crystallinity was discussed. The influence of reaction conditions and aging time on shell growth during sonochemical preparation was also discussed. The size and morphology of CdS particles and the structure and photocatalytic properties of CdS / TiO2 were characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy and photocatalytic property tests. The results show that increasing the reaction temperature and holding time can improve the crystallinity of the product during the hydrothermal process. During sonochemical synthesis of CdS / TiO2 composites, ultrasound can promote the formation of core-shell structure. Increasing the concentration of the precursor solution will precipitate TiO2 nanoparticles while obtaining CdS / TiO2 core-shell structure. CdS / TiO2 showed better catalytic performance than monocomponent materials in the degradation of methyl orange.