Fe0.5MnOx · nH2O nanolayers synthesized via successive ionic layer deposition and their use in voltammetric nonenzymatic determination of hydrogen peroxide

Abstract

In this work, the ability to synthesize the mixed iron–manganese oxide nanolayers via SILD has been shown. Aqueous solutions of potassium ferrate and manganese acetate have been served as the reagents for such synthesis. The layers have been probed via scanning electron microscopy, X-ray microanalysis, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-Vis and FTIR spectroscopy. The hydrated amorphous Fe_0.5MnO_x ∙ nH₂O layers with nanoparticle sizes of 10–20 nm have been detected at the surface, where the Fe/Mn content ratio is 0.5 and thickness increases with the number of layering cycles. The experimental data have allowed one to assume the chemical reactions occurring on the surface upon synthesis. The synthesized layers have been tested as electrodes in the voltammetric determination of H₂O₂ concentration, and the most effective electrodes are found to be those obtained after 30 SILD cycles. For them, the linear dependence of a sensor response for H₂O₂ solutions is found to be over the concentration range of 1 × 10^–8–5 × 10^–8 М. It has also been assumed that the synthesized layers can be applied as the sorbents for purification of gases and liquids; catalysts for oxidation of organic compounds, CO and NO; electrodes of chemical current sources; and so on.