Effect of copper oxide (CuO) and vanadium oxide (V2O5) addition on the structural, optical and electrical properties of corundum (α-Al2O3)

Abstract

In this work, we prepared a pure α-Al₂O₃, α-Al₂O₃/CuO (AC) and α-Al₂O₃/V₂O₅ (AV) nanocomposite. The sol-gel method was used to prepare pure α-Al₂O₃, (AC) and (AV) samples at 1200 °C. Structural, electrical, and optical properties of the prepared samples were investigated using the X-ray diffraction (XRD), UV-Visible spectrophotometer, and conductivity meter, respectively. The XRD results confirmed the crystalline nature and the presence of the hexagonal structure of α-Al₂O₃, the rhombohedra structure of CuAlO₂ and the tetragonal structure of V₂O₅. Moreover, the crystallite size of pure α-Al₂O₃ was 43.1 nm, while the crystallite size of α-Al₂O₃ in samples AC and AV nanocompsite was 24.05 nm and 34.84 nm respectively. The optical measurements showed that the band gap α-Al₂O₃ decreased significantly from 5.28 eV for pure to 3.7 and 3.4 eV to AC and AV respectively. The DC electrical conductivity (σ_d.c) values were measured for all prepared samples at room temperature. The electrical conductivity was 2.4 × 10^-7 and 1.8 × 10^-7 (Ω cm)^-1 in AC and AV nanocompsite respectively, while ionic conductivity (σ_ion) decreased from 3 × 10^-10 in pure α-Al₂O₃ to 7 × 10^-5 and 1 × 10^-5 in AC and AV nanocompsite, respectively. The results showed an improvement in the structural, optical, and electrical properties, which may make these materials a candidate for use in many applications, such as photocatalytic, gas sensors, optoelectronics, microelectronics, semiconductor devices, ……etc.