热处理温度对核-壳型SiO2@TiO2复合纳米材料光催化性能的影响

Effect of Heat Treatment Temperature on Photocatalytic Capacity of Core-Shell SiO2@TiO2 Composite Nanomaterials

采用溶胶-凝胶法在二氧化硅(SiO2)纳米微球表面负载纳米二氧化钛(TiO2),制备核-壳SiO2@TiO2复合纳米颗粒。采用X射线衍射仪(XRD)、环境扫描电子显微镜(SEM-EDS)、比表面积测定(BET)等研究手段对样品的矿物组成、结构形貌进行了表征,并考察了其光催化活性。结果表明:溶胶-凝胶法后期的热处理明显提高了核-壳SiO2@TiO2复合纳米颗粒光催化降解亚甲基蓝溶液的能力,其中,经过400℃热处理的样品催化效果最好,对质量浓度为20mg/L的亚甲基蓝溶液90min的降解率达到96.27%。

The core-shell SiO 2@TiO 2 composite nanoparticles were prepared by sol-gel process with(TiO 2)coated on the surface of silica nanoparticles.XRD,SEM-EDS and BET were adopted to analyze the structure and morphology of as-prepared samples,and their photocatalytic activities were also investigated.The results show that SiO 2@TiO 2 composite nanoparticles with core-shell structure can be successfully synthesized by sol-gel method.The photocatalytic capacity of SiO 2@TiO 2 core-shell is significantly improved by heat treatment.When the heat treatment temperature is 400℃,the composite photocatalytic material shows the highest photocatalytic activity under UV light,and the degradation rate of methylene blue(20 mg/L)for 90 min can reach to 96.27%.