Showing 4 results for Photocatalysis
P. Karimi, K. S. Hui, K. Komal,
Volume 7, Issue 3 (8-2010)
Abstract
Abstract:
(Y2O3) and ethyl acetate as a mineralizer by hydrothermal method at a low temperature (T=.230°C, and
P=100bars).The as-prepared powders were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared
Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), UV-V Spectroscopy and Chemical Oxygen Demand
(COD) of the sewage water, respectively. The results show that hydrothermal method can greatly promote the
crystallization and growth of YVO4 phase. XRD pattern clearly indicates the tetragonal structure and crystallanity. An
FTIR spectrum of the YVO4 shows the presence of Y-O and V-O bond, respectively. The presence of these two peaks
indicates that yttrum vanadate has been formed. UV-V is absorption spectra suggesting that YVO4 particles have
stronger UV absorption than natural sunlight and subsequent photocatalytic degradation data also confirmed their
higher photocatalytic activity.
In this paper, YVO4 powder was successfully synthesized from Vanadium Pentaoxide (V2O5), Yttrium Oxide
M.j Kadhim, Fatima Allawi, M. A. Mahdi, Sami Najah Abaas,
Volume 19, Issue 3 (9-2022)
Abstract
Zinc Oxide (ZnO) nanorods and titanium dioxide (TiO2) nanostructures thin films were prepared onto glass substrates by the chemical bath deposition (CBD) method. The ZnO was structured as nanorods (NRs) while TiO2 was formed as nanoflowers plate as confirmed by Field-Emission Scanning Electron Microscope (FESEM) images. The ZnO/Fe3O4 and TiO2/Fe3O4 nanostructures thin films were prepared via drop-casting Fe3O4 NPs onto the grown ZnO and TiO2 nanostructures thin films. The diameter of Fe3O4 NPs was deposited onto ZnO NRs thin films and TiO2 nanostructures thin films was ranged from 8nm to 59nm with dominated range between 10nm to 30 nm. The crystalline structure of prepared samples was investigated through X-ray diffraction (XRD) method. However, the particles size of Fe3O4 was estimated by XRD as well as FESEM images was around 22 nm. The photocatalytic activity of the as-prepared ZnO/Fe3O4 and TiO2/Fe3O4 nanostructures thin films was investigated against methylene blue (MB) dye at room temperature with a pH value of 10 under different exposure time by visible light. The photodegradation rate of MB dye by ZnO/Fe3O4 and TiO2/Fe3O4 nanostructures thin films was higher than that obtained by ZnO and TiO2 nanostructures thin films. The best photodegradation rate of MB dye was 100% after exposure time of 180 min was obtained by ZnO/Fe3O4 nanostructures thin film whereas it was 82% for TiO2/Fe3O4 nanostructures thin films after exposure time of 240 min.
Aicha Kater, Saâd Rahmane, Fatima Djenidi, Hala Nezzal, Nourelhouda Mokrani, Elhachmi Guettaf Temam, Hadjer Barkat, Boutheina Saadi, Brahim Gasmi,
Volume 21, Issue 0 (3-2024)
Abstract
Zinc oxide (ZnO) thin films have garnered significant interest for their applications in optoelectronics and environmental remediation due to their exceptional optical, electrical, and photocatalytic properties. However, the high resistivity and rapid charge recombination of pure ZnO necessitate doping to enhance its performance. In this study, ZnO thin films doped with tin (Sn) and aluminum (Al) were synthesized via a cost-effective pneumatic spray technique. The structural, optical, and morphological properties of the films were systematically characterized using X-ray diffraction (XRD), UV-Vis spectrophotometry, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results indicate that Sn and Al doping significantly influence ZnO’s crystallinity, bandgap energy, and surface morphology. The optimal crystallite size was obtained for 1 wt.% Sn (37.98 nm) and 5 wt.% Al (48.63 nm), while excessive doping (>3 wt.%) introduced microstrain (10.41 × 10⁻⁴ for Sn and 7.13 × 10⁻⁴ for Al), reducing crystallinity. The optical bandgap decreased from 3.254 eV (pure ZnO) to 3.142 eV (1 wt.% Sn) and 3.152 eV (5 wt.% Al), accompanied by increased Urbach energy (0.34 eV for 5 wt.% Al). The highest optical transmittance (86%) was observed for 3 wt.% Al-doped ZnO. Pure ZnO exhibited the highest photocatalytic efficiency, achieving 85% methylene blue degradation under solar irradiation. Langmuir adsorption modeling revealed that Sn-doped ZnO exhibited the highest adsorption capacity (1.422 mg/g), followed by Al-doped ZnO (0.617 mg/g) and pure ZnO (0.495 mg/g). These findings emphasize the critical role of doping concentration in optimizing ZnO thin films for advanced photocatalytic and optoelectronic applications.
Hella Houda, Guettaf Temam Elhachmi, Hachemi Ben Temam, Saâd Rahmane, Mohammed Althamthami,
Volume 21, Issue 4 (12-2024)
Abstract
In this study, we thoroughly examine β-Bi2O3 thin films as potential photocatalysts. We produced these films using an environmentally friendly Sol Gel method that is also cost-effective. Our research focuses on how different precursor concentrations, ranging from 0.1 M to 0.4 M, affect the photocatalytic performance of these films. We conducted a comprehensive set of tests to analyze various aspects of the films, including their structure, morphology, topography, optical properties, wettability, and photocatalytic capabilities. These tests provided us with a well-rounded understanding of the films' characteristics. To assess their photocatalytic efficiency, we used Methylene Blue (MB) as a contaminant and found that the films, particularly those with a 0.1 M concentration, achieved an impressive 99.9% degradation of MB within four hours. The 0.1 M film had a crystalline size of 39.7 nm, an indirect band gap of 2.99 eV, and a contact angle of 51.37°. Our findings suggest that β-Bi2O3 films, especially the 0.1 M variant, have promising potential for treating effluents from complex industrial dye processes. This research marks a significant step in utilizing sustainable materials to address pollution and environmental remediation challenges.
