Synthesis and Structure Characteristic of Three-dimensional Ordered Macroporous SnO_2 and SnO_2/SiO_2 Materials

By using SnCl2-2H2O and tetraethyl orthosilicate as raw materials, polystyrene colloidal crystal with diameter of 585nm as template, three-dimensional ordered macroporous (3DOM) SnO2 and SnO2/SiO2 were successfully synthesized. SEM observation shows that 3DOM SnO2 has a pore size of 453-500nm, and 3DOM SnO2/SiO2 has a pore size of 500nm. And such macropores connect with each other by small windows. Compared with the polystyrene colloidal crystal used, the 3DOM materials show shrinkage to some extent in pore size. The study indicates that it is difficult to obtain ordered pore structure when SnCl2 is used as precursor directly. But addition of tetraethyl orthosilicate or conversion of SnCl2 solution to oxi'de sol favors the formation of the highly ordered macroporous structure. XRD measurement indicates that the walls of the 3DOM materials are made of SnO2 nanoparticles with particle sizes around 17nm.