Degradation of methylene blue in aqueous dispersion of hollow titania photocatalyst: study of reaction enhancement by various electron scavengers.
Degradation of methylene blue in aqueous dispersion of hollow titania photocatalyst: study of reaction enhancement by various electron scavengers.
复制标题
DOI：
10.1016/j.jcis.2007.09.092
复制
发表时间：
2008-01
影响因子：
9.9
通讯作者：
A. Syoufian;K. Nakashima
中科院分区：
文献类型：
--
作者：
A. Syoufian;K. Nakashima
以磺化聚苯乙烯乳胶颗粒（平均直径200 nm）为模板，结合溶胶-凝胶法制备了亚微米级的二氧化钛空心球。使用0.20 mol/L的四氧化钛和25 g/L的乳胶，可以形成壳厚约15 nm、孔洞直径约150 nm的锐钛矿颗粒。通过电子清除剂对二氧化钛空心球光催化分解亚甲基蓝（MB）的增强作用，考察了二氧化钛空心球的光催化活性。电子清除剂采用无机氧化剂，如ClO−3、BrO−3、IO−4、H2O2和S2O2−8。电负性、卤素的原子半径、高活性自由基和非自由基中间体的数量的差异被证明是电子清除剂在MB光分解中产生高效率的重要标准。结果表明，各氧化剂的作用顺序为：S2O82−>IO4−>BrO3−>H2O2>ClO3−。
Submicrometer-sized titania hollow spheres have been synthesized by employing sulfonated polystyrene latex particles (averaged diameter: 200 nm) as a template in conjunction with the sol–gel method. Utilization of 0.20 mol/L titanium tetrabutoxide and 25 g/L latex led to the formation of anatase particles having shell thickness of about 15 nm and void diameter of about 150 nm. Photocatalytic activity of the titania hollow spheres was examined by focusing on its enhancement by electron scavengers in the photocatalytic decomposition of methylene blue (MB). The electron scavengers employed were inorganic oxidants such as ClO−3, BrO−3, IO−4, H2O2, and S2O2−8. Differences in electronegativity, atomic radius of the halogens, and the number of highly reactive radical and nonradical intermediates were proven to be important criteria for an electron scavenger to yield high efficiency in the MB photodecomposition. Based on the results, the effect of the oxidants used were found to be in the order of S2O82−>IO4−>BrO3−>H2O2>ClO3−.