摘要
分别以氯化锡和氯化亚锡为Sn源,使用溶胶-凝胶法制备出不同掺杂量的Sn-TiO2,比较了Sn2+与Sn4+对掺杂后TiO2可见光催化活性的影响.实验结果显示,Sn2+与Sn4+均能显著抑制TiO2晶粒生长,并促进其晶型转变.但Sn2+-TiO2的可见光催化活性却明显优于Sn4+-TiO2,这主要是Sn2+外层半充满的电子轨道结构引起的.将可见光催化活性很高的Sn2+-TiO2负载于大比表面积、高稳定性的介孔蒙脱石上,由于载体与Sn-TiO2之间发生了相互作用,负载后样品的UV-Vis光谱吸收边相对于Sn-TiO2发生了显著红移,且可见光催化活性也有大幅提高.
Two different tin salts,SnCl2-2H2O and SnCl4-5H2O,were employed in the synthesis of Sn-doped TiO2.And the crystal structures and visible-light photocatalytic activities between Sn2＋-doped TiO2 and Sn4＋-doped TiO2 were compared.The results show that both the anatase-to-rutile phase transformation temperature and the crystal growth of TiO2 are remarkably decreased by Sn dopant,and the Sn2＋ dopant shows the higher efficiency than Sn4＋ dopant.And despite the similar spectra of XRD and FTIR,Sn2＋-doped TiO2 displays higher visible-light photocata-lytic activities than Sn4＋-doped TiO2,due to the half-filled d electronic orbit of Sn2＋.Mesoporous montmorillonite was chosen as the supporting material for Sn2＋-doped TiO2,due to its high crystalization and large specific surface area.When Sn2＋-doped TiO2 was loaded on mesoporous montmorillonite,the resualtant samples had no significant difference in XRD patterns and FTIR spectra as compared with the supporting material,and no obvious peaks were found related to Sn2＋-doped TiO2.While the UV-Vis analysis shows that the adsorption edges of Sn2＋-doped TiO2 display red shift after loaded onto mesoporous montmorillonite.As a result,the resultant compound photocatalyst exhibits higher visible-light catalytic activity than unloaded Sn2＋-doped TiO2,which is due to the interactions be-tween mesoporous montmorillonite supports and Sn2＋-doped TiO2.This might provide a promising way to improve the photocatalytic activity of TiO2 with minimized cost and widened light-response region.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第9期917-922,共6页
Journal of Inorganic Materials
基金
国家自然科学基金(50574043,40772028)~~
关键词
Sn-TiO2
可见光催化活性
介孔蒙脱石
负载
Sn-doped TiO2
visible-light photocatalytic activity
mesoporous montmorillonite
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