静电自组装制备斜发沸石负载纳米TiO2吸附及光催化降解甲基橙染料研究

Electrostatically self-assembled preparation,adsorption and photodegradation of clinoptilolite supported-nano titanium dioxide materials

为了实现纳米TiO2的固定化负载,提高材料对污染物的光催化效率,采用静电自组装方法制备了天然斜发沸石负载纳米TiO2光催化材料。采用硅烷偶联剂(OCH3)3Si(CH2)3SH干法改性斜发沸石,采用30%H2O2/HOAc氧化剂将偶联剂巯基基团(—SH)氧化为易电离的磺酸基基团(—SO3H),带负电荷的沸石与钛聚合阳离子在静电引力的作用下自发地组装在一起,经一定温度的焙烧得到斜发沸石负载纳米TiO2光催化材料。采用XRD和SEM对材料进行分析和表征,采用甲基橙染料评价材料的吸附和光催化性能,结果表明:沸石负载纳米TiO2对甲基橙染料具有吸附与光催化的协同作用,静电自组装方法制备的材料的光催化性能较传统方法有所提高。

The electrostatic self-assembly method（ESAM method）was used to prepare natural clinoptilolite supported-nano titanium dioxide photocatalysts with the purpose of immobilizing nano titanium dioxide and improving the photocatalytic efficiency of the photocatalysts.（OCH3）3Si（CH2）3SH silane was modified on natural clinoptilolite by dry process.Sulfhydryl group（—SH）of the silane was then oxidized to electronegative sulfonic acid group（—SO3H）by 30% H2O2/HOAc oxidant.On the effect of electrostatic interaction,the electronegative clinoptilolite was self-assembled together with titanium polycation to form clinoptilolite-titanium dioxide compound.The natural clinoptilolite supported-nano titanium dioxide photocatalysts were obtained after the calcinations of the above samples at a certain temperature.The materials were characterized by X-ray diffraction（XRD）and scanning electron microscopy（SEM）.Methyl orange（MO）was used to estimate the adsorption and photocatalysis of the materials.The results show that the anatase begin to transform to rutile when the calcination temperature is above 600℃.Nano titanium dioxide is evenly distributed on the surface and in the pores of natural clinoptilolite.The materials exhibit a synergistic effect of adsorption and photocatalysis on methyl orange.The decoloration rate of MO solution catalyzed by samples calcined at 200℃ reaches 79.36% after illumination for 1 h.The material prepared by the ESAM method exhibits higher photocatalytic activity than that prepared by the traditional method.