Herein, a new nanocomposite adsorbent of crosslinked chitosan (CH)- glutaraldehyde (GD)/hydroxyapatite nanoparticles (HA)/sepiolite clay was fabricated by hydrothermal process to remove two anionic dyes namely remazol brilliant orange (RBO) and acid red 88 (AR88) from contaminated water. The CH-GD/HA/SP was characterized by several analytical techniques including pHpzc, BET, SEM-EDX, XRD and FTIR analyses. The specific surface area (BET) and pHpzc results were found to be 7.2 m2/g and 6.9 respectively. Three input adsorption parameters of contact time, pH and CH-GD/HA/SP dose were optimized by using Box Behnken Design (BBD). The removal efficiency of RBO and AR88 were found to be 91.5
ZnO–SnO₂ composite nanomaterials were synthesized by pulsed laser ablation in liquid (PLAL) at laser pulse energies of 200, 400, and 600 mJ using a green and surfactant-free approach. Their structural, morphological, optical, colloidal, photocatalytic, and antibacterial properties were systematically investigated. XRD confirmed the coexistence of wurtzite ZnO and rutile SnO₂ crystalline phases and revealed a reduction in crystallite size from approximately 32 to 21 nm with increasing laser energy. FESEM showed the development of finer and more uniformly distributed nanorod-like structures, while EDX indicated progressively increased Sn incorporation at higher energies. UV–Vis analysis revealed a slight increase in the estimated optical band gap from 3.24 eV at 200 mJ to 3.29 eV at 400 mJ and 3.34 eV at 600 mJ. PL measurements indicated an increased contribution of defect-related emission states, whereas DLS and zeta-potential analyses demonstrated reduced aggregation and improved colloidal dispersion for ZnO–SnO₂-600. These energy-induced modifications enhanced the photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB). ZnO–SnO₂-600 exhibited the highest apparent rate constants of 18.5 × 10⁻³ min⁻¹ for MB and 31.0 × 10⁻³ min⁻¹ for RhB, with removal efficiencies of 91.2
Bacteria-mediated metallic nanoparticle biosynthesis represents a sustainable alternative that reduces environmental impacts. Silver nanoparticles (AgNP, spherical-73 nm) were produced using Pseudomonas extremaustralis 2E-UNGS culture supernatants containing nitrate reductase. This study aimed to explore the biotechnological applications of these biogenic AgNP as a green alternative for the development of new materials. CC50 values ranged between 1.35 and 6.46 µg AgNP/mL for CRFK and A549 cells respectively. At 1 µg AgNP/mL cell pretreatment, 2-log viral reductions were registered for HSV-1, SARS-CoV-2, and CCoV, and 1-log reduction for ADV-5 and VSV. A virucidal activity with 220 µg AgNP/mL reduced viral titers by 6-log, 2-log and 5-log for HSV-1, VSV and SARS-CoV-2 respectively, showing no virucidal activity against ADV-5. AgNP fungicidal effect against Candida albicans, Candida tropicalis, and Pichia kudriavzevii revealed minimum inhibitory and minimum fungicidal concentrations of 1.49 µg AgNP/mL. Biofilm eradication and cell viability studies evidenced a dose-dependent reduction in P. kudriavzevii and C. albicans biomass, with C. tropicalis biofilm structural resistance while metabolic activity was inhibited at the highest tested AgNP concentrations. Ecotoxicity assessment revealed a 48-h LC50 for Eisenia fetida of 1.3 µg/cm² (95
Anion exchange membranes play a key role in alkaline water electrolysis for sustainable hydrogen production. In this work, we developed a novel composite membrane predominantly based on poly(vinyl alcohol), with polybenzimidazole as the second polymeric component, and modified by incorporating carbon nanotubes functionalized with MgAl layered double hydroxide as nanostructured fillers to improve membrane performance. The membranes were characterized by structural, morphological, thermal and mechanical techniques, swelling ratio, KOH and water uptake and ionic conductivity. The incorporation of the functionalized carbon nanotubes enhanced the membrane properties compared with the unmodified membrane. The results also indicate the existence of an optimum nanotube loading, at which the electrolyzer exhibited its best performance, while no further improvements were observed upon additional nanotube incorporation. From an environmental perspective, the fluorine-free nature of the polymeric matrix and the low optimal nanofiller loading are favorable material-related features, while solvent use during fabrication and membrane end-of-life remain relevant aspects for further investigation. These findings show that incorporating these nanofillers into poly(vinyl alcohol) and polybenzimidazole-based membranes provides an effective strategy for designing advanced materials for alkaline water electrolysis.
Phytofabrication of nanoparticles (NPs) in recent times has attracted researchers due to their positive attributes, like being economically feasible, safe, sustainable, and eco-friendly in comparison to the physico-chemical mode of fabrication. This study shows the successful fabrication of selenium nanoparticles (SeNPs) from Calotropis procera leaf extract. The phytofabricated SeNPs (PSeNPs) were analyzed using techniques like UV-vis spectroscopy, Photoluminescence (PL), Dynamic Light Scattering (DLS), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), and Transmission Electron Microscope (TEM). The fabrication of SeNPs was confirmed with a discernible peak at 271.5 nm, and FTIR shows the presence of functional molecules like flavonoids, terpenoids, and phenolic compounds as natural reducing and capping agents. Also, other results confirm its amorphous nature, spherical shape, and negative zeta potential (-21.6 mV). They exhibit good antioxidant activity of 77.70
