Chemical, synthesis, characterization and electrochemical properties of α‐Fe2O3/ZnO composite nano‐heterojunction for sensing application

Abstract

Low temperature hydrothermal methods have been utilized to synthesize Hematite/Zinc oxide α‐Fe2O3/ZnO composite nano‐heterojunction nanorods grown on FTO glass substrates while monitoring the effect of different concentrations of urea on the morphology of the composite nano‐heterojunction. X‐ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were used for the structural characterization of the α‐Fe2O3/ZnO different samples. UV‐visible spectroscopy was used for the characteristic absorbance versus wavelength of α‐Fe2O3/ZnO composite nano‐heterojunction which shows an absorption edge from 400 to 560 nm. X‐ray photoelectron spectroscopy (XPS) technique was applied to study of chemical composition of the α‐Fe2O3/ZnO and the obtained information demonstrated a pure phase α‐Fe2O3/ZnO has been achieved. The best efficiency among urea concentrations for the best composite nano‐heterojunction sample was achieved when using 0.2 M of urea. The electrochemical properties of the composite nano‐heterojunction were investigated using a three‐electrode electrochemical cell. Estimation of the electrochemical area shows that both the composite nano‐heterojunction and the bare α‐Fe2O3 have similar values. This confirms that the enhanced electrochemical property of the composite nano‐heterojunction is due to a synergetic effect as expected.