Controlled growth surface morphology of ZnO hollow microspheres by growth temperature

The structural and optical properties of ZnO hollow spheres with club-shaped nanorods grown on the outer and inner surfaces were investigated by using Zn powder as precursor at 475∘C. SEM, XRD, TEM and HRTEM were used to characterize the morphology and crystalline structure of the samples. Thus to realize the controlling of surface morphology, it is most essential to grow ZnO hollow spheres at different experimental conditions. Therefore, the effect of the growth temperature on surface morphology of ZnO hollow spheres should be scrutinized in detail. We grew ZnO hollow spheres by thermal evaporation at various temperatures in the range of 465–520∘C. We found that the increase in growth temperature transformed surface morphology from nanowires to club-shaped nanorods and nanograins. In addition, the increased growth temperature caused changes of optical qualities of the products.