Copper Loaded Hydroxyapatite Nanoparticles as eco‐friendly Fenton-like catalyst to Effectively Remove Organic Dyes

Abstract

In this study, natural hydroxyapatite (NHAp) was synthesized by the dissolution of phosphate rock in acidic medium and precipitated via basic solution. Then, a series of copper loaded NHAp (Cu/NHAp) were prepared using ion exchange method and employed as a novel heterogeneous Fenton-like catalyst for degradation of a toxic organic compound. The Cu/NHAp materials have been characterized by different physico-chemical techniques including XRD, XPS, FT-IR, Raman & UV–vis spectroscopies, NMR 31P, SEM, TEM and nitrogen adsorption-desorption methods. The materials exhibit a high catalytic activity for the degradation of methylene blue in the presence of H2O2 as green oxidant under basic medium. Moreover, the effects of different parameters, including pH, H2O2 concentration, catalyst loading, initial dye concentration, and temperature on the degradation kinetics were investigated and discussed in detail. Furthermore, based on the results obtained by radical quenching experiments and electron paramagnetic resonance (EPR), it was shown that hydroxyl radicals were the main reactive species responsible for MB degradation. Finally, TOC analysis, catalyst recyclability and stability confirmed that copper loaded hydroxyapatite might be an alternative Fenton-like catalyst towards organic pollutants degradation and environmental remediation.