Synthesis of Highly Monodispersed Mesoporous Tin Oxide Spheres

Abstract

Synthesis of monodispersed mesoporous tin oxide spheres and fabrication of close-packed mesoporous tin oxide opal is presented. By taking advantage of the oxidation of tin(II) chloride on the surface of monodispersed starburst carbon spheres (MSCS), which are produced using monodispersed mesoporous silica spheres as a host, nanocrystals of tin oxide accumulate into mesopores of MSCS. Calcination of the MSCS/SnO 2 composite yields monodispersed mesoporous tin oxide spheres (MMTOS) that consist of SnO 2 nanocrystals. Although the starburst structure of MSCS is lost during calcination, monodispersed spherical shape is retained. As a result of its uniformity, MMTOS can be self-assembled into a close-packed opal, which exhibits a stop band in the visible region.