Influences of solvothermal-assisted crystallization process on the microstructure and properties of SiO2-W0.02TiO2.06 composite aerogels synthesized via ambient pressure drying

Abstract

In this work, the influence of solvothermal crystallization processes on the microstructure, pore characteristic, and adsorption/photocatalysis of SiO2-W0.02TiO2.06 composite aerogels synthesized via ambient pressure drying have been investigated. It has been clarified that the composite aerogels prepared via solvothermal crystallization at 120 °C for 0.5 h and 180 °C for 3 h exhibited high-specific surface area (416–729 m2/g) and pore volume (2.26–2.70 cm3/g). With the increase of solvothermal crystallization temperature and time, the crystallinity of composite aerogels increased gradually, but excessive solvothermal crystallization time at higher temperature decreased the pore volume greatly. Furthermore, it is found that bacterial cellulose (BC) in the composite gel plays an important role in enhancing the pore volume and crystallization of the SiO2-W0.02TiO2.06 composite aerogels as a pore-expanding agent and structure-directing agent. The as-synthesized SiO2-W0.02TiO2.06 composite aerogels exhibited higher adsorption and removal efficiency for RhB than the commercial P25-TiO2, which can be ascribed to its high pore volume and specific surface area, as well as the synergistic action of adsorption and photocatalysis.