Nanostructured silver decorated hollow silica and their application in the treatment of microbial contaminated water at room temperature†
The present study describes the synthesis of mesoporous silicon dioxide (silica) spheres decorated with silver nanoparticles and the investigation of their antimicrobial properties. The sol–gel method was used for the synthesis of mesoporous hollow silica spheres using tetraethyl orthosilicate (TEOS) as the silica source. Uniform hollow spheres (∼300 nm) with a thin shell of silica (∼40 nm) and a high surface area (516 m2 g−1) were obtained after calcination at 550 °C. Furthermore, silver nanoparticles were decorated on the surface of the hollow structure of silica by the adsorption of silver ions at various concentrations followed by reduction using sodium borohydride. Microscopic studies showed that metallic silver was uniformly distributed over the surface of the hollow silica. The as-obtained silver decorated hollow silica exhibited an excellent antibacterial activity against Escherichia coli (E. coli) compared to that of bare hollow silica, which makes them suitable candidates for the economical treatment of bacteria-contaminated water.