A Facile Approach to Fabrication of ZnO-TiO2 Hollow Spheres

A facile approach for the fabrication of hierarchically nanostructured hollow spheres composed of mixed metal oxides (ZnO-TiO2) has been demonstrated. The employed protocol involves coating of the functionalized polystyrene (PS) template beads with the successive layers of ZnO and TiO2 nanoparticles, respectively, followed by the calcination of resulting PS/ZnO-TiO2 core shell composite particles at elevated temperature Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been employed to evidence the fabrication of the monodisperse, intact, and closed ZnO-TiO2 hollow spheres. Presence of both ZnO and TiO2 phases in the ceramic shell of resulting hollow spheres has been confirmed by electron energy loss mapping analysis. Phase purity of the ZnO and TiO2 phases of the ceramic shell has been studied by X-ray diffraction analysis. Brunauer-Emmett-Teller (BET) method reveals the specific surface area and the average pore diameter of hollow spheres as 59.63 m(2)/g and 3 nm, respectively Photocatalytic properties of the fabricated ZnO-TiO2 hollow spheres has been investigated for the degradation of organic dyes and compared with those of ZnO and TiO2 hollow spheres.