Iron-copper oxide nanoparticles supported on reduced graphene oxide for the degradation of cyclophosphamide by photo-Fenton reaction

Abstract

Bimetallic (Fe-Cu) and reduced graphene oxide (rGO)/FeCu catalysts at 0.2% wt. were developed by a co-precipitation method, modifying the Fe-Cu molar proportions (i.e., Fe40Cu60, Fe20Cu80 and Fe10Cu90) and tested for the degradation of the cytostatic drug, cyclophosphamide (CP) in aqueous solution using the photo-Fenton process (UV-Vis). Physicochemical characterization was carried out by complementary techniques (gas adsorption, SEM, TEM, XRD, XPS) and results were correlated with the catalytic performance. The effect of pH on the degradation of the contaminant and the catalyst stability (metal leaching) were studied. The results point out the synergetic effect of the rGO/FeCu catalysts in comparison to the monometallic catalysts or without carbonaceous material. The best performance was achieved with the rGO/Fe10Cu90 catalyst achieving 82% of CP degradation at natural pH regarding 87% obtained under acid conditions (pH 3). This fact avoids the usual acidification of the solutions during Fenton-like processes and prevent the metal leaching, increasing the stability of catalysts, as demonstrated after consecutive degradation cycles, maintaining efficiency above 75%. Cytotoxicity tests certificated the low toxicity of the by-product derived from the photo-Fenton process.