Supercritical preparation of hexagonal γ-alumina nanosheets and its electrocatalytic properties

Alumina precursors were prepared via a sol–gel process by refluxing aqueous solutions containing urea and 0.4 M Al3+ (the [urea]/[Al3+] ratio was 3.0). The obtained precursor precipitates were dried in supercritical ethanol. The resultant γ-alumina nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometry (FTIR). Hexagonal sheet γ-alumina (γ-Al2O3) nanoparticles with a diameter of 8.48 nm were successfully prepared. The electrocatalytic properties of the nano-γ-alumina/carbon paste electrode for oxidation of alizarin in 1.0 M H2SO4 solution have been investigated by cyclic voltammetry (CV), and excellent electrocatalytic activity was observed.

Graphical abstractHexagonal γ-alumina nanosheets have been successfully prepared by supercritical ethanol drying. Its high electrocatalytic activity was confirmed by the voltammograms of 5 mM alizarin at different scan rates.Figure optionsDownload full-size imageDownload as PowerPoint slide