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, Zeinhom M. El-Bahy Biomass Conversion and Biorefinery, 2025 The 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.
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, et al. Biomass Conversion and Biorefinery, 2025 This 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, Ahmed S. Elzaref Biomass Conversion and Biorefinery, 2024 The 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 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, Ahmed Shafek Elzaref Scientific Reports, 2023 The 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.
