Photocatalytic degradation of atrazine under visible light using Gd-doped ZnO prepared by supercritical antisolvent precipitation route

Supercritical antisolvent precipitation route was employed for the first time to prepare Gd-doped ZnO photocatalysts to be tested in the photocatalytic degradation of atrazine under visible light. Physical-chemical characterization data show that the addition of Gd does not change the crystalline structure of ZnO and that Gd3+ ions are successfully introduced into the semiconductor lattice, leading to a decrease of band gap energy value and inducing the formation of oxygen vacancies inside the ZnO framework. The photocatalytic performances of the as-prepared samples are determined by analyzing the degradation of atrazine under visible light irradiation. The doped photocatalyst with a Gd loading of 0.7 mol% exhibits the highest photocatalytic activity under visible light irradiation compared to the other prepared photocatalysts. The possible reaction mechanism of the optimized photocatalyst is also discussed.