Hydrothermal Synthesis of Gadolinium (Gd) Doped Cerium Oxide (CeO2) Nanoparticles: Characterization and Antibacterial Activity

Abstract

This present study has been described the synthesis, characterization and antibacterial activity of gadolinium doped cerium oxide nanoparticles. The nanoparticles were prepared by hydrothermal method with various concentrations of gadolinium ranges from 2 mol% to 8 mol%. The X-ray diffraction (XRD) pattern revealed the face-centered cubic structure with crystalline size of 58.3 nm to 57.4 nm with increasing the concentration of gadolinium (2 mol% to 8 mol%). The Ce-O chemical bonding nature was confirmed using Fourier transform infrared spectrometer (FTIR). The field emission scanning electron microscope (FESEM) exhibited fascinating shapes like cube and square of nanoparticles. UV spectrophotometer used to measure the optical behaviors of CeO 2 nanoparticles. Band-edge absorption of CeO 2 nanoparticles blue shifted upon increasing the gadolinium concentration as compared to undoped CeO 2 nanoparticles. The emission behavior of nanoparticles was examined by photoluminescence (PL) spectroscopy. PL spectra reveals a peak shift of CeO 2 emission upon gadolinium doped due to oxygen defect. The gadolinium doped CeO 2 nanoparticles showed better antibacterial activity against the pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Bacillus cereus and Salmonella typhi.

Polymer Thermal Treatment Production of Cerium Doped Willemite Nanoparticles: An Analysis of Structure, Energy Band Gap and Luminescence Properties

“…The spectrum reveals that the undoped sample has greater absorption of Si–O vibrational bands, and this owed to the strong chemical affinity of silica [ 28 , 32 , 52 , 53 , 54 ]. As the dopant (1–5 mol% Ce 3+ ) is substituted into the host matrix, the stretching mode of Ce–O was expected to appear around 500–550 cm –1 as reported by Syed Khadar et al [ 55 ]. However, there were no such peaks on the spectra, and this is correlated to the low concentration of the dopant [ 28 , 50 ].…”

“…The peak in the blue region at 480 nm observes a little shift to 485 nm between 800 and 1000 °C. This behavior was ascribed to the enhancement in crystal feature of the material and subsequent deterioration of the ZnO crystal structure to form willemite [ 86 ].The impact of the Ce 3+ ions dopant (1–5 mol%) on the optical emission of willemite phosphor is taken into consideration, from the emission spectra shown in Figure 16 b, the doped samples demonstrated a strong emission peak at 400 nm coming from the guest ion (the dopant) which is due to the transition of an electron from localized Ce 2f state to the valence band of O 2p [ 55 ]. It is evident that the addition of cerium dopant in the willemite matrix decreased the intensity of the green emission at 530 nm and the blue emission at 485 nm.…”

“…Additionally, an emission peak at 422 nm ascribed to the O 2 defects had disappeared due to the introduction of the dopant. Moreover, the emission intensity progressively increased with the addition of the dopant concentration [ 38 , 55 ].…”

Palladium‐Supported Nanoceria: A Highly Efficient Catalyst for Solvent‐Free Selective Oxidation of Ethylbenzene to Acetophenone

“…The absorption band at 1368.79 cm −1 corresponds to physically adsorbed water molecules . The bands at 892 cm −1 and 538 cm −1 produced by CeO 2 are typical peaks for Ce−O stretching vibrations …”

“…The direct bandgap was calculated using the Tauc plot [αhν vs hν], where α is the absorption coefficient and hν is the photon energy. The absorption band of CeO 2 with band‐edge at around 450 nm occurs as a result of the charge transfer transitions from 2p orbital of O 2− to 4 f orbital of Ce 4+ indicating the overlap of Ce 4+ transition with the Ce 3+ [4f 1 5d 1 ] transition . However, on loading Pd the nanocomposite shows absorption in a broad range in the visible region and as a result of this red shift, the bandgap is narrowed.…”