Synthesis and thermal treatment of cu-doped goethite: oxidation of quinoline through heterogeneous fenton process

Abstract

Samples of Cu-doped goethites were prepared and characterized by Mössbauer spectroscopy, XRD, TPR and BET surface area measurements. Mössbauer data showed the incorporation of Cu2+ in the goethite structure, and this cation-doping caused a significant decrease of the chemical reduction temperature in the TPR process. The catalytic behavior of these Fe1−xCuxOOH materials was investigated for the H2O2 decomposition to O2 and the Fenton-like reaction to oxidize quinoline. It was observed that Cu2+ in this goethite and also the thermal treatment with H2 produced a strong increase in the catalytic activity during the quinoline oxidation. The successive hydroxylation of quinoline during this oxidation strongly suggests that highly reactive hydroxyl radicals are generated during the reaction involving H2O2 on the Cu-goethite grain surface, also confirming that these materials are efficient heterogeneous Fenton catalysts.