Adsorption and heterogeneous Fenton degradation of 17α-methyltestosterone on nano Fe3O4/MWCNTs in aqueous solution

A novel catalyst, inverse-spinel ferroferric oxide nanoparticles decorated multiwalled carbon nanotubes (Fe3O4/MWCNTs) was successfully prepared, and applied for the adsorption and degradation of trace artificial androgen 17 alpha-methyltestosterone (MT) in the presence of H2O2. The regular growth of ferroferric oxide crystal on multiwalled carbon nanotubes was achieved by in situ oxidation of Fe2+ in hot alkaline solution. The catalyst was characterized by BET. XRD, TEM, XPS and Raman spectroscopy. The effects of initial pH, catalyst loading, oxidant concentration and iron leaching on the degradation of MT were investigated. The Fe3O4/MWCNTs showed higher ability of adsorption and degradation efficiency of MT than bare Fe3O4 in the batch degradation experiment. The degradation efficiencies increased with the initial pH decreasing in the wide pH range of 8.0-3.5. Further, the catalyst showed stable catalytic activity, fairly good mechanic stability and convenient recycling. Negligible iron leaching showed the reused Fe3O4/MWCNTs withstood the oxidation. The enhanced degradation efficiency of Fe3O4/MWCNTs may relate to the enrichment of trace MT molecules by MWCNTs in the vicinities of active sites. (C) 2011 Elsevier B.V. All rights