A facile and general fabrication method for organic silica hollow spheres and their excellent adsorption properties for heavy metal ions

This paper presents a facile and general method for fabrication of organic silica hollow spheres by co-hydrolysis and condensation reactions of TEOS and other silane coupling agents under the catalysis of ammonia. Silane coupling agents were first pre-hydrolyzed to form micelles. When TEOS was added, a sol-gel reaction takes place between TEOS and the Si-OH and methoxy groups, at the surfaces of the micelles to form porous silica shells, producing organic silica hollow spheres. Taking vinyl silica hollow spheres as an example, the as-obtained hollow spheres exhibited considerably high adsorption properties for Pb2+ and other heavy metal ions.