Synthesis of high photoreactive flower-like ZnO nanoneedles assembly with exposed nonpolar {1010} facets oriented by carbon spheres

Abstract

In this work, carbon spheres (CSs) derived from glucose by simple eco-friendly process were used to create a multiphase environment for precipitation reaction to obtain flower-like C-doped ZnO (C-ZnO) nanoneedles assembly. It was found that the presence of carbon spheres can affect the crystal orientation and morphology of ZnO. When the additive amount of carbon spheres was 13 wt%, one-dimensional (1D) needle-like single crystal C-doped ZnO were obtained, which exposed with higher proportion of nonpolar {1010} facets (51%) than that of pristine ZnO (46%), and C-Zn and C-O-Zn bonds were formed. Compared with pristine ZnO prepared by direct precipitation method (ZnO-DPM) without carbon spheres, carbon doped ZnO exhibited higher light absorption ability and smaller band gap width due to the formation of surface defects. The photocatalytic degradation rate of methyl orange over 13 %C-ZnO was 99.98% for 3 h under the irradiation of UV lamp (15 W), almost 1.3 times higher than that of pristine ZnO-DPM. Even after repeating use for 3 times, the degradation rate of methyl orange can be kept as high as 99%. The present study offers a new preparation method for high photoreactive ZnO with exposed nonpolar {1010} facets by precipitation reaction.