Abstract
The conducted studies compared the influence of polymers (PVA, PVP, PEG and g-C3N4) added to the copper(II) and iron(III) cations co-precipitation environment during the preparation of copper(II) ferrite precursors on the phase compositions of CuFe2O4 + Polymer samples heat-treated at 700 °C, their electrochemical reduction, and the electrocatalytic activity of the resulting Fe-Cu composites. The structure and morphological features of CuFe2O4 + Polymer samples after heat treatment (HT) and electrochemical experiments were studied using XRD analysis and electron microscopy. Thermogravimetric studies were performed for the polymers and copper ferrite precursors. The results indicate that the thermal degradation products of PVA and g-C3N4 polymers induce a partial decomposition of copper ferrites during HT, yielding crystalline phases of copper and iron, thereby significantly decreasing the duration of the subsequent electrochemical reduction of these samples. "Pure" CuFe2O4 and samples containing other polymers remain stable at 700 °C. Electrochemical reduction of CuFe2O4 + PVP and CuFe2O4 + PEG samples result in a more complete reduction of iron cations than in other samples, which is favourable for intensifying the electrohydrogenation of 4-nitrophenol on Fe-Cu composites formed from these samples. The fabrication of a single product, 4-aminophenol, is confirmed by UV-vis spectra.