Anionic polystyrene (PSt) latex particles were synthesized by emulsion polymerization of methacrylic acid and styrene (St). The anionic PSt particles were surface treated with vinyl trimethoxysilane in a mixture of ethanol and water. PSt/TiO2 composite particles doped with Ag2O were then prepared through hydrolysis of tetrabutyl titanate and AgNO3 using the surface treated PSt particles as templates. Hollow Ag-TiO2 particles were successfully prepared by treating the PSt/TiO2 composite microspheres at 180 ℃, after which they were dried and calcined at 500 ℃. The morphology of the PSt/TiO2 particles and crystal structure of the Ag-TiO2 hollow particles were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Photocatalytic activity of the Ag-TiO2 hollow particles for Rhodamine B (RhB) degradation was tested under ultraviolet (UV, 365 nm) and UV-visible (370-760 nm) light. Under UV light, RhB degradation was increased by about 11% when Ag-TiO2 particles with molar ratio nAglnTi of 0.1% were used compared with pure TiO2 hollow particles. Under UV-visible light, RhB degradation was increased by about 30% for Ag-TiO2 composite particles with nAg/n-n of 1.0% and 2.0%.%通过甲基丙烯酸与苯乙烯的乳液聚合制备了表面载有阴离子的聚苯乙烯(PSt)纳米乳胶粒.在乙醇与水的混合溶剂中,用硅烷偶联剂乙烯基三甲氧基硅烷对其进行表面改性.以此乳胶粒为模板,加入钛酸四丁酯和硝酸银制备了Ag2O掺杂型聚苯乙烯/二氧化钛(PSt/TiO2)复合微球.对该微球在1 80℃进行液相预处理、干燥、500℃煅烧等步骤制备了Ag掺杂型Ag-TiO2复合粒子.通过扫描电镜(SEM)、透射电镜(TEM)和X射线衍射(XRD)等手段对PSt/TiO2复合粒子及Ag-TiO2空心粒子的形貌及晶体结构等进行了表征.考察了Ag-TiO2复合粒子在紫外光(365 nm)与紫外-可见光(370-760 nm)下对罗丹明B(RhB)降解的催化活性,结果表明,与不含银的TiO2空心微球相比,在紫外光照射下,银含量(nAg/nπ)为0.1％的Ag-TiO2复合粒子对RhB的降解率提高了11％左右;在紫外-可见光照射下,nAg/nTi为1.0％和2.0％的Ag-TiO2复合粒子对RhB的降解率提高了30％左右.
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