凹凸棒黏土-SnO2-TiO2复合材料的制备及其光催化性能

Synthesis of Attapulgite-SnO_2-TiO_2 Nanocomposites and Their Photocatalytic Property

以凹凸棒黏土(Att)为基体,通过原位溶胶-凝胶工艺,将SnO2-TiO2复合氧化物负载于凹凸棒黏土表面制备凹凸棒黏土复合型光催化剂(Att-SnO2-TiO2)。采用XRD、BET、TEM等分析测试技术对产物进行了表征。结果表明,SnO2-TiO2复合氧化物均匀地负载于凹凸棒黏土表面,其平均粒径约10 nm;经过复合氧化物负载改性后,凹凸棒黏土的表面形貌得到明显改善,产物的负载效果好、比表面积大。以光催化降解甲基橙为探针,研究了凹凸棒黏土复合光催化剂的光催化性能。结果表明,凹凸棒黏土复合光催化剂显示出优异的光催化性能,其光催化活性顺序为Att-SnO2-TiO2>Att-SnO2>Att-TiO2。以性能较佳的Att-SnO2-TiO2为催化剂光降解甲基橙30 min,结果表明,甲基橙的降解率达99%。实验表明,Att-SnO2-TiO2复合光催化剂可重复利用。

Attapulgite（Att） was used as the matrix of SnO_2-TiO_2 hybrid oxide to synthesize a novel kind of composite photocatalyst（Att-SnO_2-TiO_2） by depositing SnO_2-TiO_2 hybrid oxides on the surface of Att via an in stiu sol-gel technique.The obtained products were characterized by means of X-ray diffraction（XRD）,BET surface area and transmission electron microscope（TEM）.Experimental results show that the surface of attapulgite was evenly covered by SnO_2-TiO_2 nanocomposites with particle size around 10 nm.The modification of attapulgite by loading these composites resulted an improvement of its surface morphology while retaining its high surface area.Photocatalytic removal of methyl orange under ultraviolet radiation was studied in the presence of Att composites.Results show that the Att composite photocatalysts presented preferable photocatalytic property,and the photoactivity of the composite photocatalyst decreased in a sequence of Att-SnO_2-TiO_2Att-SnO2Att-TiO2.The Att-SnO_2-TiO_2 exhibited excellent activity and the decomposition rate of methyl orange was up to 99% within 30 min when the Att-SnO_2-TiO_2 powder was used as the photocatalyst.The repeated use of the composite photocatalyst was also confirmed.