Magnetic nanocomposite fabrication using banana leaf sheath Biofluid: Enhanced Fenton catalytic activity towards tetracycline degradation

Abstract

Impregnation of banana leaf sheath biomass along with its biofluid helps to produce a magnetite nanocomposite of better magnetic strength and tetracycline degradation. • A simple, novel and one-pot fabrication of metal oxide@carbon nanocomposite is demonstrated by utilizing biofluids in biomasses as capping agents. • Capping of ferric ions by biofluid held in banana leaf sheath enhanced their uptake and distribution in the host carbonaceous precursor and assisted fabrication of iron oxide nanoparticles loaded carbon of high magnetic saturation. • Impregnation of iron ions with dry biomass is not as effective as with the fresh one, and subsequent carbonization produced carbon of lesser magnetic strength. • Iron oxide nanoparticles supported on activated carbons are used as heterogeneous Fenton catalysts for the degradation of tetracycline antibiotic. Utilization of biofluids available in plant biomass for uniform distribution of metal cation into carbonaceous precursor, exemplified by that of ferric into banana leaf sheath, followed by carbonization is attempted for the first time in this work. Magnetic iron-oxide nanoparticles incorporated carbon composite prepared by this method (MBLF: Magnetic Banana Leaf sheath carbon-Fresh) is of higher magnetic saturation (26.12 emu. g −1 ), but a similar procedure with dry biomass (MBLD: Magnetic Banana Leaf sheath carbon-Dry) yielded a composite of lesser magnetic strength (12.53 emu. g −1 ). The composites were characterized by FT-IR, N 2 -adsorption, VSM, XRD, PES and TGA techniques and used as heterogeneous catalysts for the activation of hydrogen peroxide (HP) towards degradation of tetracycline (TC) antibiotic. Higher iron content, which is found to be mainly in the form of Fe 3 O 4 , reflected in higher pseudo-first order rate constant for MBLF than MBLD. Oxidations of TC mainly occurred through hydroxy radicals with both catalysts and significant activity is retained after three cycles of operations.