Soft-Template Synthesis and Characterization of ZnO₂ and ZnO Hollow Spheres

Abstract

Zinc peroxide (ZnO2) hollow spheres of 100−200 nm diameter were synthesized by a simple hydrothermal method by using H2O2 and ZnO powder as reagents without the assistance of any surfactant. O2 bubbles in situ generated by the decomposition of H2O2 served as a soft template in the formation of ZnO2 spheres. Zinc oxide (ZnO) hollow spheres were obtained by heat treatment of ZnO2 hollow spheres at 180 °C for 10 h in air. The products were characterized by XRD, FT-IR, TEM, HRTEM, and FESEM. The transition temperature of ZnO2 to ZnO was determined to be 229 °C by TG-DTA. Photoluminescence (PL) properties of the products were investigated and the origin of the two peaks at 392 and 448 nm in the PL spectrum of ZnO2 was discussed. Furthermore, the growth mechanism of the ZnO2 hollow spheres was discussed in detail.