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 (σd.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 (σion) 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.

Optical, structural and antibacterial properties of phase heterostructured Fe2O3–CuO–CuFe2O4 nanocomposite

“…The Fe 2 O 3 –CuO–CuFe 2 O 4 nanocomposite (NC) was synthesized using the sol–gel method 20 , 35 – 38 . Initially, two separate solutions were prepared: one with Cu(NO 3 ) 2 ·3H 2 O (5.798 g in 30 mL of ethanol) and another with Fe(NO 3 ) 3 ·9H 2 O (9.69 g in 30 mL of ethanol), keeping a molar ratio of 1:1.…”

“…Introducing a new phase to a composite material can alter its electronic properties. Metal oxide nanocomposites are prepared using various methods such as hydrothermal synthesis 15 , co-precipitation 16 , self-combustion 17 , ultrasonic-assisted routes 18 , and the sol–gel method 19 , 20 . The sol–gel method, in particular, is preferred for its low cost, speed, and simplicity, requiring no expensive equipment.…”