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.