中文摘要：

以钛酸四丁酯为源，采用苯胺-丙酮原位生成水溶胶-凝胶法，在乙醇超临界干燥过程中用部分水解的钛醇盐和硅醇盐对TiO2凝胶进行超临界修饰制备了具有核/壳纳米结构的块体TiO2/SiO2复合气凝胶.制备的复合气凝胶具有优异的机械性能，其杨氏模量可达4.5 MPa.复合气凝胶同时具有极好的高温热稳定性.经过1000°C热处理后，线性收缩由纯TiO2气凝胶的31%降至复合气凝胶的10%，且比表面积由纯TiO2气凝胶的31 m2·g^-1提升至复合气凝胶的143 m2·g^-1.此外，该复合气凝胶经1000°C热处理后具有优异的光催化降解亚甲基蓝的性能.其优异的光催化性能得益于TiO2/SiO2复合气凝胶1000°C处理后高的比表面积和小的颗粒尺寸.优良的耐热性能、力学性能和光催化性能使获得的具有核/壳纳米结构的TiO2/SiO2复合气凝胶在光催化领域具有良好的应用前景.

英文摘要：

Core/shel nanostructured monolithic TiO2/SiO2 composite aerogels were prepared by the aniline-acetone in situ water formation sol-gel method. Titanium（IV） n-butoxide was used as a precursor fol owed by supercritical modification with partial y hydrolyzed titanium alkoxide and tetraethoxysilane during ethanol supercritical fluid drying. The obtained composite aerogel showed excel ent mechanical strength with a Young′s modulus of 4.5 MPa. The composite aerogel exhibited excel ent heat resistance. After heat treatment at 1000 °C its linear shrinkage decreased from 31%for the TiO2 aerogel to 10%for the composite aerogel. The specific surface area increased from 31 m2·g^-1 for the TiO2 aerogel to 143 m2·g^-1 for the composite aerogel. The composite aerogel exhibited excel ent photocatalytic performance during the degradation of methylene blue after heat treatment at 1000 °C. Its excel ent photocatalytic property is attributed to its high specific surface area and the smal particle size of the composite aerogel after heat treatment at 1000 ° C. The enhanced heat resistance, mechanical strength, and photocatalytic performance makes the obtained core/shel nanostructured TiO2/SiO2 composite aerogel a promising candidate for photocatalytic applications.