A comparative study of a series of ferrite nanoparticles as heterogeneous catalysts for phenol removal at neutral pH

This study aimed at understanding and assessing the effect of structural specifications on catalytic properties of several ferrite nanoparticles as the heterogeneous Fenton-like catalysts. Thus, a number of synthetic M-ferrite (where M = Zn, Mn, Fe and Cu) catalysts were compared for efficiency against phenol removal in the presence of hydrogen peroxide. It was found that the copper ferrite is more active than the other studied ferrites for phenol elimination at neutral pH. The effect of pH was studied in pH values of 3, 6, and 10, while the highest phenol removal rate over the Cu-ferrite catalyst was observed at pH 6. Studying the effect of different parameters and catalyst properties on the reaction rate suggested that the hydroxyl radical generation is not the only factor to control the reaction rate, but the roles of surface adsorption of the pollutants and the catalyst specifications are also significant. Besides, in agreement with the previous reports, it was concluded that the number of surface active sites is related to the number of surface hydroxyl groups, which results in the higher surface adsorption and hydrogen peroxide activation. (C) 2016 Elsevier B.V. All rights reserved.