TiO2-SiO2气凝胶制备及其降解对硝基苯酚研究

Study on Synthesis of TiO2-SiO2 Aerogel and Its Degradation for P-Nitrophenol

以钛酸四丁酯为钛源,稻壳灰为硅源,采用超声辅助溶胶-凝胶法经常压干燥制备了具有可见光响应的TiO2-SiO2复合气凝胶,通过X射线衍射、场发射扫描电镜、透射电镜、全自动比表面积分析、傅立叶红外和紫外可见光漫反射光谱研究了气凝胶在不同温度热处理后结构性能的变化,以及其在超声辅助作用下光降解对硝基苯酚(PNP)废水的性能。结果表明,超声辅助溶胶-凝胶法制备的TiO2-SiO2气凝胶在常压干燥过程中能有效降低孔坍塌;超声空化能量可使气凝胶形成Ti-O-Si键,拓宽TiO2光响应范围至可见光;超声暗反应-光催化方法有效降低PNP分子的表观活化能,提升光催化效能。

The TiO2-SiO2 aerogel with visible light response was prepared by ultrasonic-assisted sol-gel method with ambient pressure drying,the tetrabutyl titanate as titanium source and rice husk ash as the silicon source.The change of structural performance of the aerogel after heat treatment with different temperature was characterized by XRD,FESEM,TEM,BET,FTIR and UV-Vis DRS,and the photocatalytic performance of p-nitrophenol wastewater was studied under the assistance of ultrasound.The results showed that the composite aerogel prepared by ultrasonic-assisted sol-gel method could effectively reduce the hole collapse in the process of atmospheric pressure drying.The ultrasonic cavitation energy could make the silicon-titanium bond and broaden the optical response range to visible light of titanium dioxide.Ultrasonic dark reactions-photocatalytic method could effectively reduce the apparent activation energy of p-nitrophenol molecules and improve the photocatalytic efficiency.