One-step polyoxometalate-assisted solvothermal synthesis of ZnO microspheres and their photoluminescence properties

With the assistance of Keggin-type polyoxometalate (POM) H3PW12O40·nH2O (PW12), ZnO microspheres have successfully been synthesized by a direct route, using zinc acetate dihydrate solid and dilute PW12 absolute ethanol solution at 120 °C for 24 h. The effects of PW12 concentration and reaction time were investigated. The results showed that PW12 played a vital role for the formation of the ZnO microspheres during the solvothermal treatment and the original framework of PW12 was not destroyed after the solvothermal treatment. Finally, the room temperature photoluminescence (PL) spectrum of the ZnO microspheres exhibited a sharp and strong ultraviolet (UV) emission at 390 nm and a quite weak visible emission at around 520 nm, respectively.