High photocatalytic performance of high concentration Al-doped ZnO nanoparticles

With increasing demands for environmental protection, photocatalyst has attracted great attentions, and ZnO based photocatalyst is an attractive system to study. Doping with other elements can significantly enhance the photocatalytic activity, conductivity and transmittance of ZnO. However, it is difficult to synthesize high doping concentration ZnO because of the high formation energy. In this work, high doping concentrations (up to 20 mol%) Al-doped ZnO (AZO) were prepared via sol-gel combustion method, which showed excellent photocatalytic activities, several times more efficient than previous reports. The nanoparticles containing 20% Al already showed unprecedented absorption capacity, leading to a great decrease of MO concentration from 200 to 2.7 mg/L, and further photodegrade MO thoroughly within 30 min irradiation. The mechanism of photocatalysis was also analyzed. XRD, TEM and EDX were used to demonstrate that Al has doped into ZnO crystal structure. (C) 2016 Elsevier B.V. All rights reserved.