Characterizations of pure and eu-doped ZnO aerogels nanostructures elaborated by a modified sol gel process

Abstract

Herein we report on the structural and optical properties of pure and Eu-doped (3% at.) ZnO aerogels nanostructures (ZnO-ans) synthesized by sol-gel associated with drying at supercritical conditions of isopropanol (254 °C, 54 bars). The samples were investigated using X-ray diffraction (XRD), SEM, UV-visible spectroscopy, FTIR and photoluminescence (PL). XRD studies exhibit the formation of a high crystal quality ZnO wurtzite hexagonal structure. The UV-visible measurements point out that the absorption intensity and the band gap energy increase after Eu-doping. FTIR analysis confirms the formation of ZnO phase and reveals a shift toward longer wavenumber of the Zn-O absorption band after Eu -doping. SEM images show that Eu3+ ions lead to change the morphology of ZnO crystalline from pastille to sphere. PL measurements reveal a decrease of UV luminescence intensity and an increase of the visible one due to Eu-doping.