TiO_2-SiO_2 composite aerogels with different contents of SiO_2 were synthesized through a sol-gel route with tetrabutyl titanate and tetraethyl orthosilicate as the raw materials.In combination with solution aging and pinhole drying processes,monolithic TiO_2-SiO_2 composite aerogels were prepared via ambient drying,and their microstructure and the physicochemical properties were studied by scanning electron microscopy,BET method and X-ray diffraction analysis.It is found that the composite aerogels have l...