Ahmed Shafek Mohammed Elzaref

@azhar.edu.eg

Chemistry department, Faculty of science
Al-Azhar university



           

https://researchid.co/ahmadelzaref
7

Scopus Publications

Scopus Publications

  • Metal complexes with thiosemicarbazone derivative and isatine: A promising new class of materials for biomedical and environmental applications
    Ahmed E. Hassan, Salwa A.H. Albohy, Ahmed S. Elzaref, Ahmed S. Elfeky, Esmail M. El-Fakharany, Ahmed K. Saleh, Ammar M. Mahmoud, and Walid E. Elgammal
    Elsevier BV


  • Gallium-doped titania nanotubes as advanced photocatalysts and biopesticides: a path to water purification and vector control
    Ahmed S. Elzaref, Ahmed S. Elfeky, Hassan A. El-Adawy, Mohamed A. Awad, and Zeinhom M. El-Bahy
    Springer Science and Business Media LLC
    AbstractThe release of Rose Bengal (RB) dye poses a significant threat to aquatic ecosystems, necessitating sustainable water treatment solutions. This study introduces a novel photocatalytic approach utilizing titania nanotubes (TNTs) doped with varying contents of gallium oxide (Ga₂O₃, 0–5%) via a hydrothermal method. Characterization techniques, including FTIR, XRD, TEM, SEM, EDX, and XPS, confirmed the formation of nanotubular structures with enhanced surface area and defect states. The total organic carbon (TOC) measurement indicated effective mineralization of RB dye. Among the synthesized photocatalysts, the 1% Gallium-doped titania nanotubes (Ga-doped TNTs) achieved optimal RB degradation, decomposing 97% of the dye within 110 min under UV illumination, owing to improved charge separation and synergistic effects between Ga and TNTs. Furthermore, Ga-doped TNTs demonstrated superior efficacy in mosquito control, with 100% larvicidal mortality observed at 400 °C compared with only 57.2% for TNTs. Similarly, the pupicidal mortality rate at 72 h increased from 26.2% (TNTs) to 60.8% (Ga-doped TNTs-400). The findings emphasize the dual functionality of Ga-doped TNTs as efficient photocatalysts for water purification and eco-friendly biopesticides, presenting a promising strategy for environmental remediation and vector control.

  • Synthesis of activated carbon composited with Egyptian black sand for enhanced adsorption performance toward methylene blue dye
    Ahmed Salah Elkholy, Mohamed Saber Yahia, Mohamed Abdelsamei Elnwawy, Hosny Anwar Gomaa, and Ahmed Shafek Elzaref
    Springer Science and Business Media LLC
    AbstractThe present study reports the feasibility of the synthesis of a novel porous composite adsorbent, prepared from olive stone activated carbon (OS400) and garnet (GA) mineral impregnations (referred to as OSMG). This composite (OSMG) was applied for its ability to adsorb a macromolecular organic dye. The composite’s structural characteristics were evaluated using various techniques such as Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy equipped with Energy Dispersive X-ray spectroscopy (SEM–EDX), X-ray diffraction (XRD), and a Fourier transform infrared spectrometer (FT-IR). The specific surface area of the garnet (GA), (OS400), and (OSMG) were found to be 5.157 mg⋅g−1, 1489.598 mg⋅g−1, and 546.392 mg⋅g−1, respectively. The specific surface area of the new composite (OSMG) was promoted to enhance the adsorption of methylene blue (MB). Experiments were conducted under various conditions, including contact time, initial dye concentration, adsorbent dosage, pH, and temperatures. Data from these experiments were analyzed using several adsorption models including Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R). The results indicated that, the adsorption fit best with the Freundlich model and that the adsorption process followed a pseudo-second-order kinetic mechanism. Additionally, the thermodynamic analysis indicated the adsorption of MB onto garnet(GA) adsorbents is endothermic, while the sorption onto (OS400) and (OSMG) is an exothermic and non-spontaneous process. The OSMG composite can be used for at least five cycles without significant loss of adsorptive performance, and can easily be separated from the water after treatment.

  • Thione tautomer of hydrazone-carbodithioate chelator-derived Cu(II) and Zn(II) complexes as potential antibacterial agents: DFT computations and UV-assisted photocatalytic degradation of Rose Bengal dye
    Ahmed S. Elzaref, Walid E. Elgammal, Abanoub Mosaad Abdallah, Saedah R. Al-Mhyawi, Haitham A. Abdellatif, Amr M. Abdou, Essam M. Eliwa, Islam Ibrahim, and Ahmed S. Elfeky
    Elsevier BV

  • Harnessing the potential of modified cellulosic pumpkin seed hulls as affordable biosorbents for cationic dye removal from aqueous solutions: adsorption kinetics and isotherm studies
    Ahmed K. Hady, Medhat E. Owda, Ragab E. Abouzeid, Hassan A. Shehata, Ahmed S. Elzaref, and Ahmed S. Elfeky
    Springer Science and Business Media LLC
    AbstractThis investigation focuses on examining the adsorption behavior of crystal violet dye on cellulose (CS) and its modified forms, including cellulose loaded with nicotinic acid (CSN) and cellulose loaded with thiourea (CST). Batch experiments were performed to analyze the adsorption process, while various characterization techniques, such as Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), were utilized to assess the structural and morphological changes in the cellulose materials. The findings reveal that the adsorption process follows a pseudo-second-order kinetic model, indicating a chemical adsorption mechanism. Additionally, the Langmuir isotherm model suggests monolayer adsorption on cellulose surfaces. Thermodynamic analysis demonstrates that the adsorption process is spontaneous and exothermic for CS and CSN, whereas it is endothermic for CST. The characterization techniques employed provide valuable insights into the structural modifications and porous properties of cellulose materials. Overall, this study underscores the potential of modified cellulose materials to effectively remove dyes in wastewater treatment applications. Notably, thiourea-loaded cellulose CST exhibits superior adsorption capacity with removal percentages of 78.2% compared to CS and CSN, whose removal percentages were 76.45% and 76.72%, respectively, suggesting the promising role of CST in dye removal. These findings contribute to a comprehensive understanding of crystal violet dye adsorption on cellulose and its modified forms, thereby paving the way for future research on the application of modified cellulose materials in wastewater treatment processes.

  • Green synthesis and characterization of aluminum oxide nanoparticles using Phoenix dactylifera seed extract along with antimicrobial activity, phytotoxicity, and cytological effects on Vicia faba seeds
    Ahmed K. Saleh, Abdelghany S. Shaban, Mohamed A. Diab, Dominique Debarnot, and Ahmed S. Elzaref
    Springer Science and Business Media LLC
    AbstractThe present study assessed the green synthesis of aluminum oxide nanoparticles (Al2O3-NPs) by using aluminum (Al) foil waste as an Al source and date palm seed extract as a reducing and stabilizing agent. Several methodologies were employed to investigate Al2O3-NPs, encompassing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX) analysis. The UV–visible spectroscopy analysis revealed the presence of an absorption peak at a wavelength of 264 nm, providing evidence for the successful green synthesis of the Al2O3-NPs. The XRD analysis revealed that the average size of the Al2O3-NPs was 32 ± 2.57 nm and had a rhombohedral structure. The EDX facilitated the identification of the elemental composition of the sample, which was found to consist of 40.37% Al and 31.56% O, confirming the high purity of the Al2O3-NPs powder. Furthermore, it was noted that the Al2O3-NPs exhibited the greatest antibacterial efficacy against Candida albicans (21 ± 1.85 mm), but no discernible antimicrobial effect was recorded against Klebsiella pneumoniae at higher concentrations of Al2O3-NPs. No significant variation in the germination of faba bean seeds was observed upon treatment with Al2O3-NPs. The observed mitotic index in the treatment group was determined to be significantly lower compared to the control cells, based on the duration and dosage of Al2O3-NP exposure. In contrast, for micronuclei (MN) and the prevalence of chromosomal abnormalities, there is a noticeable upward trajectory in this phenomenon. Finally, Al2O3-NPs are employed in a variety of applications, such as biomedical and agriculture.

  • Synthesis and Characterization of Chitosan/ZrO<inf>2</inf> Nanocomposite and Its Application in the Removal of Rose Bengal Dye
    Ahmed Thabet, Ahmed Elfaky, Wael Mohamed, Ahmed El-Zaref, and Zein Elbahy
    Egypts Presidential Specialized Council for Education and Scientific Research

  • Induced effects of gamma irradiation on activated carbon derived from Hyphaene Thebaica husks as a potential adsorbent for Chlorpyrifos pesticide-air purification
    Ahmed Elzaref, Mohamed Yahia, Hanan Youssef, Ahmed Elfeky, and Magdy Awad
    Egypts Presidential Specialized Council for Education and Scientific Research

  • Enhancement of photocatalytic and biological activities of chitosan/activated carbon incorporated with TiO<inf>2</inf> nanoparticles
    Medhat E. Owda, Ahmed S. Elfeky, Ragab E. Abouzeid, Ahmed K. Saleh, Mohamed A. Awad, Haitham A. Abdellatif, Fakher M. Ahmed, and Ahmed S. Elzaref
    Springer Science and Business Media LLC

  • Efficient adsorption of chlorpyrifos onto modified activated carbon by gamma irradiation; A plausible adsorption mechanism
    Mohamed S. Yahia, Ahmed S. Elzaref, Magdy B. Awad, Ahmed M. Tony, and Ahmed S. Elfeky
    Walter de Gruyter GmbH
    Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.

  • Multifunctional cellulose nanocrystal /metal oxide hybrid, photo-degradation, antibacterial and larvicidal activities
    Ahmed S. Elfeky, Salem S. Salem, Ahmed S. Elzaref, Medhat E. Owda, Hassan A. Eladawy, Ahmed M. Saeed, Mohamed A. Awad, Ragab E. Abou-Zeid, and Amr Fouda
    Elsevier BV

  • Adsorption of Dye from Wastewater onto ZnO Nanoparticles-Loaded Zeolite: Kinetic, Thermodynamic and Isotherm Studies
    Ahmed Samer Elfeky, Hanan Farouk Youssef, and Ahmed Shafek Elzaref
    Walter de Gruyter GmbH
    Abstract The adsorption process of methylene blue (MB) and its removal from aqueous solution at initial pollutant concentration range of 1–7 ppm was investigated. Zeolite-A (Z) and its ZnO-loaded species (Z/ZnO) were prepared via microwave technique from natural resource and applied for dye removal. The loading of ZnO was governed by the cation exchange property of zeolite, followed by calcination. Experimentally, Z and Z/ZnO were tested using X-ray Diffraction (XRD), Fourier-Transform Infrared (FTIR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and N2 adsorption-desorption. The examined parameters such as concentration of dye, contact time, ZnO dose and solution pH were traversed. Three isothermal models were analyzed. Kinetic studies indicated that, the adsorption of MB matched with pseudo-second order model. The maximum removal efficiency at pH 3, increased from 67.8% for Z to 94.8% for Z/ZnO modified with 3% ZnO loads (Z/ZnO(3%)). Parameters such as ΔH, ΔS, ΔG, S* and Ea were thermodynamically calculated. Langmiur isotherm and pseudo-second order models were the best fitting for the obtained data. The results indicated that, the adsorption of MB dye is spontaneous and endothermic, the removal efficiency is favored by increasing the temperature. ZnO-zeolite has much higher adsorption capacity for eliminating MB dye than that of the un-loaded zeolite.

  • Plasma O <inf>2</inf> modifies the structure of synthetic zeolite-A to improve the removal of cadmium ions from aqueous solutions
    Alaa FAHMY, Ahmed ELZAREF, Hanan YOUSSEF, Hassan SHEHATA, Magdy WASSEL, Jörg FRIEDRICH, Fabienne PONCIN-EPAILLARD, and Dominique DEBARNOT
    The Scientific and Technological Research Council of Turkey (TUBITAK-ULAKBIM) - DIGITAL COMMONS JOURNALS
    The present study addresses the removal of cadmium ions (Cd(II)) from aqueous solutions at a pH of 7.5 using zeolite-A activated by exposure to oxygen plasma. The activation process was performed over a wide range of plasma powers (10, 20, 30, and 40 W) and exposure times (30 to 360 s). Oxygen plasma cannot chemically modify zeolite to a considerable extent, but it can clean the surface, open blocked pores, and induce the formation of additional OH groups via exposure to humidity in ambient air. Therefore, Cd ion removal is increased by approximately 10% with the plasma treatments. Infrared-attenuated total reflectance spectroscopy, X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy were applied to analyze the changes in the surface structure and properties of the samples.