Facile synthesis of TiO2/Ag composite aerogel with excellent antibacterial properties

In this study, the effective TiO 2 /Ag composite antibacterial aerogel powder is prepared by facile sol–gel method and ethanol supercritical technology. The surface morphology, structural properties, and chemical components are monitored by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and energy disperse spectroscopy (EDS). Meanwhile, absorbance spectra and specific surface area of TiO 2 /Ag composite aerogel are characterized by UV-Vis spectra and Brunauer–Emmett–Teller. The TiO 2 /Ag composite aerogel with Ti/Ag molar ratios of 10:1, 30:1, 50:1 are measured for its antibacterial property by using Escherichia coliform ( E.coli ) and Staphylococcus aureus ( S. aureus ). The results show that the size of TiO 2 and Ag nanoparticles are 40 nm and 25 nm, respectively. Simultaneously, the obtained composite aerogel with a porous structure possessed a surface area of 148 m 2 /g, an average pore size 11.5 nm, and a pore volume 0.39 cm 3 /g. With the increase of Ag content, the antibacterial properties of composite aerogel are greatly improved compared with pure TiO 2 aerogel. When Ag/Ti molar ratios was 1:10, the highest antibacterial rate can up to 99%, and the inhibition bands of E. coli and S. aureus are 23 mm and 19 mm, respectively. Schematic representation of growth mechanism of TiO 2 /Ag composite aerogel (a) and antibacterial performance test (b, c)