Nitric oxide removal by action of ZnO photocatalyst hydrothermally synthesized in presence of EDTA

ZnO samples with different morphologies were synthesized in presence of ethylenediaminetetraacetic acid disodium salt (EDTA) at 200 °C under hydrothermal treatment. The morphology of the nanostructures obtained was modified by changing the concentration of EDTA and the reaction time. The effect of the reaction conditions on the morphology, crystallization as well as in the optical and textural properties of the ZnO samples was investigated by using scanning electron microscopy (SEM), X-ray powder diffraction (XRD), UV-Vis absorption spectroscopy (DRS) and adsorption-desorption N2 isotherms (BET). The ZnO performance as photocatalyst was evaluated in the oxidation reaction of nitric oxide (NO) under UV irradiation. The study revealed that ZnO samples with morphology of nanoplates showed significantly higher NO removal than other ZnO samples with morphologies of rods and flower-type. The ZnO sample with the highest photocatalytic activity was measurement using different mass and its stability was tested after several photocatalytic cycles. By the use of scavenger species was determined the participation mainly of the superoxide anion (O2.-) and holes (h+) in the photocatalytic oxidation process of NO.