Structural, Optical, and Magnetic Properties of Cobalt-Doped ZnAl2O4 Nanosheets Prepared by Hydrothermal Synthesis

Abstract

Nanomaterials with collective optical and magnetic properties are called smart or functional materials and have promising applications in many fields of science and technology. Undoped and Co-doped ZnAl2O4 were prepared using a co-precipitation-assisted hydrothermal method. A systematic investigation was carried out to understand the effects of the Co concentration on the crystalline phase, morphology, and optical and magnetic properties of Co-doped ZnAl2O4. X-ray diffraction confirmed the cubic spinel structure with the Fd3m space group, and there was no impurity phase. X-ray photoelectron spectroscopy of Co-doped ZnAl2O4 confirmed the existence of Zn, Al and O, and the Co in the optimized sample of ZAO-Co-3 confirmed the oxidation state of cobalt as Co2+. Transmission electron microscopy of pure and Co-doped ZnAl2O4 revealed micro-hexagons and nanosheets, respectively. The optical absorption results showed that the bandgap of ZnAl2O4 decreased with increasing Co concentration. The hysteresis loop of Co-doped ZnAl2O4 revealed clear ferromagnetic behavior at room temperature. The as-prepared materials are suitable for energy storage applications, such as in supercapacitors and fuel cells. This work aims to focus on the effect of cobalt ions in different concentrations on structural, optical and magnetic properties.

Fabrication, characterization, and antibacterial activity of ferrite, chromite, and aluminate nanoparticles

“…Figure 8(d) displays the core spectra of O-1 s, which consist of two peaks and reflect the −2 site occupancy of O. The former peak is attributed to lattice oxygen (O L ) contribution in the M-O bond, while the latter peak is attributed to the oxygen defect indicating the presence of some vacant oxygen (O V ) [105,106]. Now regarding the different elements in the samples, the spectra illustrated in figures 9(a)-(c) show six peaks in Fe-2p, four peaks in Cr-2p, and two peaks in Al-2p.…”

“…Similarly, the FM phase of chromite NPs can be created from the cationic disorder [16]. On the other hand, in the case of aluminate NPs, the FM phase mainly depends on three causes such as the raise of free electrons and holes (as a result of doping), the presence of secondary phase, and the existence of defects like Zn and O interstitials or vacancies [106].…”

Sol-gel Synthesis of CaZnAl2O4 Ceramic Nanoparticles and Investigation of their Properties

“…The obtained diffraction data was well-matched with the JCPDS File Nos. 00-050-0426 and 36-1451 (Gurugubelli, T. R. et al, 2021;Reem S, Khaleel. et al, 2020).…”

“…The obtained diffraction data was well-matched with the JCPDS File Nos. 00-050-0426 and 36-1451 (Gurugubelli, T. R., et al, 2021;Reem S. Khaleel, et al, 2020). The mean crystallite size of the CaZnAl 2 O 4 nanoparticles was 13 as computed using Scherrer's equation (Rahman, Ashiqur.…”