Solvothermal synthesis of core–shell ZnO hollow microhemispheres

Core–shell ZnO hollow micro-hemispheres with core-nanoparticles and hexagonal nanoplates at the outer layer were synthesized through a facile solvothermal route assisted by poly(styrene sulfonic acid) sodium salt (PSS). The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results indicate that PSS and the starting content of the reactants have influence on the morphologies of ZnO. To investigate the formation process of ZnO hollow micro-hemispheres, the ZnO products collected at different times were characterized by XRD and SEM. The growth mechanism of the hollow ZnO micro-hemispheres may be attributed to the preferred adsorption of PSS on (0 0 1) plane of ZnO and the Ostwald ripening process.