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Öğe Enhancing photocatalytic efficiency through iron doping: a comprehensive study on zirconium vanadate synthesis and characterization(Springer, 2024) Alyousef, Haifa A.; Hassan, Ahmed M.; Ali, Ahmed S.; Issa, Shams A. M.; Zakaly, Hesham M. H.This study investigated the synthesis, structure, optical properties, and photocatalytic performance of novel Fe-doped zirconium vanadate nano-powders (Fe-doped ZrV2O7 NPs). The nano-powders were synthesized using the hydrothermal method to optimize their photocatalytic efficiency with varying Fe concentrations (0 to 9 mol%). Structural analysis using X-ray diffraction (XRD) revealed that the undoped ZrV2O7 exhibited a monoclinic ZrO2 structure while increasing Fe concentrations introduced new peaks corresponding to the zinc-blende structure of Fe2VO4 and the orthorhombic phase of V2O5. Optical characterization using UV–visible spectroscopy showed that the bandgap decreased from 4.02 eV for undoped samples to 3.11 eV for the sample with nine mol% Fe, improving its light absorption capacity. Photocatalytic experiments were conducted using methylene blue (MB) as the model organic pollutant under visible light irradiation (500 W) at room temperature and neutral pH. Degradation efficiency was evaluated by monitoring the reduction in MB absorbance at 665 nm. The ZrV-9 sample exhibited the highest photocatalytic efficiency, with a degradation rate of 72% within 30 min. Additionally, the catalyst demonstrated excellent stability and recyclability, retaining 90% of its efficiency after five cycles. These findings highlight the potential of Fe-doped ZrV2O7 nano-powders as efficient and durable photocatalysts for organic pollutant degradation under visible light. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.Öğe Influence of substrate temperatures on the microstructural, morphological, and optoelectronic characteristics of Cu3N/ITO thin films intended for solar cell applications(Springer, 2024) Alyousef, Haifa A.; Zakaly, Hesham M. H.; Hassan, Ahmed M.Solar cells are crucial for renewable energy, with indium tin oxide (ITO) commonly used as a window layer. Copper nitride (Cu3N) is a promising material, yet research on both materials together is scarce. This study investigates the influence of substrate temperatures on the properties of Cu3N/ITO thin films, a critical factor for solar cell efficiency. Cu3N thin films were deposited onto ITO substrates using rf magnetron sputtering in an argon/nitrogen atmosphere at substrate temperatures ranging from room temperature (RT) to 150 degrees C. We found that increasing the substrate temperature significantly enhanced the microstructural, morphological, and optoelectronic properties of the Cu3N/ITO films. XRD analysis revealed a polycrystalline nature with a cubic phase structure, and the average crystallite size increased from 17 nm (RT) to 37 nm (150 degrees C). SEM images showed a corresponding change in the surface morphology with increasing substrate temperatures. The optical properties of the films were studied in a range between (300 to 2500 nm) using UV-Vis-NIR spectroscopy, which showed a decrease in the optical energy gap from 2.62 eV (RT) to 2.23 eV (150 degrees C), indicating a tunable band structure. Additionally, optoelectronic properties containing optical conductivity, electrical conductivity, optical carrier concentrations, optical mobility, refraction loss, and optical resistivity were significantly affected by substrate temperature. Findings highlight the crucial influence of substrate temperatures and offer substantial potential for improving the efficiency of Cu3N/ITO-based solar cells.Öğe Optimizing structural, morphological, optical, and photon attenuation properties of AZO nanocrystals for radiation shielding(Elsevier, 2024) Almousa, N.; Hassan, Ahmed M.; Issa, Shams A. M.; Obiedallah, Fatma M.; Zakaly, Hesham M. H.The study has been carried out to check the influence of different Al contents (0, 2, 4, 6, 8, and 10 at.%) in the structure and morphology of Al-doped ZnO nanocrystals (AZO NCs) by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXS), as well as the optical properties by using the UV-vis-NIR double-beam spectrophotometer within the wavelength of 300-1100 nm. XRD pattern shows a polycrystalline behavior and strong orientation and shifts in the peaks toward higher diffraction angles for AZO NCs with a hexagonal structure, and the crystallite size reduces from 28 +/- 4 nm to 16 +/- 4 nm as the Al concentration rises. SEM analysis revealed that the AZO NCs exhibit dense crystal grains with sharp edges. With increasing Al concentration, AZO NCs exhibited an increase in the optical bandgap from 3.16 eV to 3.57 eV. The study of the photon attenuation characteristics and radiation shielding properties of the AZO NCs has been assessed. For varying concentrations of Al, the corresponding mass attenuation coefficient (GMAC) and linear attenuation coefficient (GLAC) were determined for different energies of the incident photons. The calculated results showed that the GMAC value dropped with a rise in the Al concentration and a fall in photon energy. However, the GLAC value increased with the increasing population density. This further extends to studying the effect of higher Al contents on reducing the effective half-value layer (GHVL) based on the thickness of the shielding. Accordingly, the present work extends further to find the effective atomic number (Zeff) and mean free path (GM & Oslash;) with respect to correlations in photon energy and Al content. However, the trends differed across the energies for evaluating the exposure buildup factor (EBF). But, in general, the present findings from this study can be used to develop Pb-free, effective radiation shielding materialsÖğe Optimizing the structure and optoelectronic properties of cuprite thin films via a plasma focus device as a solar cell absorber layer(Royal Soc Chemistry, 2024) Hassan, Ahmed M.; Alyousef, Haifa A.; Zakaly, Hesham M. H.Solar cells are of growing importance as a renewable energy source, and cuprite (Cu2O) stands out as a promising material due to its cost-effectiveness, abundance, and appealing optoelectronic characteristics. This research uses diverse analytical methods to adjust the influence of the number of plasma focus shots on Cu2O films' crystal structure, morphology, and optoelectronic attributes. X-ray diffraction revealed that both Cu2O and CuO films exhibited a polycrystalline nature with cubic (111), (110), and (200) orientations. Morphological analysis unveiled that film surface characteristics were impacted by the number of shots, leading to the formation of smaller Cu2O grains as the number of shots increased. The transmittance spectra of Cu2O thin films displayed remarkable optical transparency, approximately 80%. The optical bandgap of the films was determined to be 2.57 eV, decreasing to 2.08 eV with an increase in the number of shots, aligning well with values reported for photovoltaic absorber layers. Optoelectronic properties, including optical and electrical conductivities, optical mobility, optical carrier concentrations, refraction loss, optical resistivity, plasmon, and damping frequencies, were computed. The results underscore the significant impact of the number of plasma focus shots and hold great promise for enhancing the performance of Cu2O-based solar cells.Öğe Structural, linear/nonlinear optical characteristics and radiation shielding effectiveness of Cu4O3/Cu2O dual-phase thin films: Influence of oxygen flow rate in reactive sputtering process(Elsevier ltd, 2024) Issa, Shams A. M.; Hassan, Ahmed M.; Algethami, Merfat; Zakaly, Hesham M.H.In the present work, we investigated the impact of oxygen flow rate on the structural, linear, and nonlinear optical characteristics while also evaluating the radiation shielding effectiveness during reactive radio frequency (rf) sputtering in the deposition of Cu4O3/Cu2O dual-phase thin films. Microstructural analysis revealed distinct changes with increased OFRs, switching from a Cu2O cubic structure phase to a Cu4O3 tetragonal structure phase. The XRD patterns revealed good crystallinity, and the crystallite size of the film reduced from 28 nm to 22 nm, and the microstrain exhibited an opposing trend as the oxygen flow rate increased. In contrast, investigating the optical properties of dual-phase Cu4O3 and Cu2O thin films using UV-Vis-NIR spectroscopy revealed intriguing trends in the absorbance spectra, absorption coefficient, and extension index. The apparent bandgap increases from 2.0 eV to 2.62 eV with increasing oxygen flow rates. In addition, nonlinear optical parameters, including the nonlinear refractive index n(2) linear, nonlinear sensitivity (chi(1) and chi(3)), and nonlinear absorption coefficient beta(c) were calculated to demonstrate the applicability of these materials. The dual-phase structure of the films enhances their potential for effective radiation shielding. Our findings provide valuable insights into the design of properties of Cu4O3/Cu2O dual-phase thin films for applications ranging from photoelectric and nonlinear optical devices to radiation shielding effectiveness.
