Synergistic effect of iron and copper in hydroxyapatite nanorods for Fenton-like oxidation of organic dye

Abstract

In this report, we deal with the synthesis process of pure hydroxyapatite (HAp) nanorod by facile hydrothermal method, followed by dual metal doping (Fe-Cu@HAp) via an ion-exchange method. This novel heterogeneous Fe-Cu@HAp nanocatalyst was employed in the degradation of polluting dyes through an advanced oxidation process involving H2O2 as an environmentally benign oxidant. The structural, morphological, and optical properties of the as-synthesized nanocatalysts were examined by various techniques such as PXRD, FTIR, Raman, UV-DRS, SEM-EDS, TEM, and XPS. It was observed that the Fe-Cu@HAp exhibited superior catalytic activity compared to pristine HAp for the degradation of organic pollutants in the presence of green oxidant H2O2. Moreover, several reaction parameters like initial solution pH, H2O2 dosage, catalyst loading on the kinetics of the degradation process were investigated. The degradation of dyes with Fe-Cu@HAp followed first-order kinetics and the rate constants for methylene blue and malachite green were 0.05113 min−1 and 0.0613 min−1 respectively, which were higher than those with pure HAp. Furthermore, quenching experiments were carried out to confirm the involvement of hydroxyl radicals generated in the degradation process.