Synthesis of mesoporous SiO2 aerogel/WxTiO2 nanocomposites with high adsorptivity and photocatalytic activity

• SiO2 aerogel/WxTiO2 mesoporous particles were synthesized by hydrothermal method.
• The –CH3 groups on the surface of aerogel can be decreased by hydrothermal reaction.
• Increasing SiO2 aerogel content could improve adsorptivity of the composite powders.
• The ethanol/water ratio in the solution has effects on the porosity of the particles.

Mesoporous SiO2 aerogel/WxTiO2 nanocomposites with high adsorptivity and photocatalytic activity were prepared by hydrothermal deposition method using SiO2 aerogel as carrier. The morphology and microstructure of the SiO2 aerogel/WxTiO2 nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption measurements. The results indicated that the SiO2 aerogel/WxTiO2 nanocomposites exhibited sponge-like network-structure with higher pore volume and anatase TiO2 crystallinity. Increasing the SiO2 aerogel content and ethanol/water volume ratio in the precursor solution is favorable for improving the specific surface area and pore volume of SiO2 aerogel/WxTiO2 composite particles. Under the conditions of Si/Ti mol ratio >0.6 and ethanol/water volume ratio >1:3, the specific surface area and pore volume of the as-prepared SiO2 aerogel/WxTiO2 nanocomposites could attain to 195.7–271.3 m2/g and 0.86–1.11 mL/g, respectively. Moreover, the as-prepared SiO2 aerogel/WxTiO2 nanocomposites exhibited higher adsorptivity and photocatalytic activity. Particularly, the synthesized SiO2 aerogel/WxTiO2 nanocomposite sample 0.9STW-1:3 (Vethanol/Vwater = 1/3) exhibited highest efficiency for removing the Rhodamine B in the simulated wastewater. In addition, the as-prepared SiO2 aerogel/WxTiO2 composites still exhibited higher adsorption efficiency and photocatalytic activity after 4 cycles.

SiO2 aerogel/WxTiO2 mesoporous particles were successfully synthesized by hydrothermal method. The –CH3 groups on the surface of aerogel can be decreased during hydrothermal reaction. Increasing SiO2 aerogel content promote the adsorptivity of the composite powders, and the ethanol/water volume ratio in the precursor solution have effects on the porosity of the composite powders. The synthesized SiO2 aerogel/WxTiO2 mesoporous particles exhibited higher adsorptivity and photocatalytic activity simultaneously.Figure optionsDownload as PowerPoint slide