Synthesis of hierarchically structured ZnO spheres by facile methods and their photocatalytic deNOx properties.

This paper presents novel and facile methods for the fabrication of a series ZnO spheres by template-free, carbon template and hydrated-salt assisted solvothermal process, respectively. Phase purity and crystalline structure of the products were studied by X-ray diffraction analysis. SEM was employed to investigate the morphology and the fabrication of the monodisperse. BET analysis revealed that the as-prepared samples possessed huge specific surface area. UV-vis diffuse reflectance spectroscopy showed that these ZnO hollow spheres have a higher absorption. The as-prepared samples showed excellent photocatalytic activity for the decomposition of NOx gas under both visible-light and UV light irradiation (λ>510, 400, 290nm), being superior to that of commercial TiO2 powders.