Large-scale synthesis of ZnO microhollowspheres and their optical properties

ZnO microhollowspheres (MHs) were synthesized by evaporation of a mixture of zinc, graphite, and zinc oxide powders. The microstructures of the resultant MHs have been characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), X-ray diffraction, and photoluminescence (PL). The PL results indicated that the green emission peak at 510 nm of the MHs was higher and broader than that of the nanocombs, which was due to oxygen vacancies formed in the MHs. In addition, the mechanism of ZnO MHs was discussed in detail.