Nanobiocomposites d’oxydes (Al/Fe) modifiant une électrode à pâte de carbone pour le stockage d’énergie et l’électroanalyse de trois colorants anioniques (méthylorange, rouge alizarin et rouge Congo)

Abstract

In this work, nanoparticles of iron and/or aluminum oxides were synthesized from the secondary resource, orange peels, with the aim of improving their ability to absorb anionic compounds and their suitability as energy storage material. The nanomaterials obtained from the use of orange peels are those based on iron oxide (FeOP), aluminum oxide (AlOP), and mixed iron oxide and aluminum (AlFeOP). They were characterized scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and by thermal gravimetric analysis. These analyses confirm the formation of the nanoparticles during the synthesis. The nanomaterials have a relatively high porosity and varied shapes in the presence of iron oxide and/or aluminum nanoparticles incorporated in the orange peel. The structural properties of the nanomaterials have contributed to the design of carbon paste electrodes for the detection of anionic dyes of environmental importance. The sensors developed with the nanomaterials of iron oxide, aluminum oxide, and the mixed material were named CPE/FeOP, CPE/AlOP and CPE/AlFeOP respectively. The characterization of these materials using two electrochemical probes, [Ru(NH3)6] and [Fe(CN)6] , has highlighted their good affinity for the cationic probe. The modified electrodes were then applied to the quantitative electroanalysis of methyl orange (MO), alizarin red (AR), and Congo red (CR), three highly toxic textile dyes. The electroanalysis of azo compounds shows that the detection limits obtained with CPE/FeOP, CPE/AlOP, and CPE/AlFeOP are 2.9×10 mol.L , 3.2×10 mol.L , 1.3×10 mol.L , for MO 3+ 3- -8 -1 -8 -1 -8 -1 -8 -1 -8 and 1.2×10 mol.L , 2.4×10 mol.L , 2.6×10 , for AR respectively. Finally, after optimizing -1 -8 -7 -1 of the detection parameters on the CPE/FeOP sensor, a limit of detection (LOD), was obtained in CR solution calculated for a signal/background ratio of 3 equal to 2.8.10 mol.L . The synthesized materials were then evaluated to assess their capabilities as semiconductors. CPE/AlFeOP is the modified electrode that has the best specific capacitance value in the 0.5 mol.L KH PO solution and therefore has a good internal resistance. AlFePO seems to be a -1 24 good material for the fabrication of fuel cells.