Nanomaterials are materials at the nanometric scale that have distinctive functionalities and properties. Due to their unique properties relative to traditional materials, nanomaterials attract great interest from researchers. ZnO-based nanomaterials especially demonstrate versatility, accessibility, biocompatibility and low toxicity. In recent years, there has been a growing interest in developing eco-friendly and sustainable approaches for synthesizing nanomaterials. In the development of ecological techniques for their synthesis, using natural resources is a popular choice. Employing egg white for ZnO nanoparticle synthesis represents an environmentally method that uses a natural resource. The great advantage of green synthesis using egg white is that it is a cost-effective, renewable, and bio-degradable resource that offers biocompatibility. Egg white is rich in proteins, amino acids, and other biomolecules that possess reducing properties. These biomolecules interact with metal ions, leading to the reduction and nucleation of nanoparticles. Additionally, the proteins in egg white act as capping agents, stabilizing the nanoparticles and preventing their aggregation. The proteins of white albumen have different functional groups and maintain product attributes, such as dispersion and stability. This paper focuses on the characterization of ZnO nanoparticles obtained by the assisted synthesis of egg white. This study explores the potential of ovalbumin, the major protein in egg white, as a template for the synthesis of nanostructured ZnO. The synthesis process utilized egg white from different sources (commercially raised hens, home-raised hens, and ducks) and varying zinc nitrate concentrations (1M and 2M) to evaluate their influence on nanoparticle morphology and size. Various complementary techniques are employed to analyze the resulting nanostructures: XRD, SEM, and ATR-FTIR. Also, antibacterial properties are investigated. This study underscores the viability of different egg whites as a green resources for synthesizing nanostructured ZnO and contributes to the development of sustainable nanotechnology approaches.

Sustainable and eco-friendly synthesis methods for nanoparticles are crucial for advancing green nanotechnology. This study presents the biogenic synthesis of zinc oxide (ZnO) and magnesium oxide (MgO) nanoparticles using ovalbumin, an abundant and non-toxic protein from egg white. The synthesis process was optimized by varying metal ion concentrations to control particle size and morphology. Characterization using ATR-FTIR, XRD, SEM, and UV-VIS confirmed the successful formation of uniform, well-crystallized nanoparticles with sizes ranging from 7.9 to 13.5 nm. ZnO nanoparticles exhibited superior antimicrobial efficacy against Escherichia coli and Enterococcus faecalis, while MgO nanoparticles showed enhanced potential environmental remediation. These findings highlight ovalbumin as a versatile agent for the green synthesis of ZnO and MgO nanomaterials, with promising applications in the medical, environmental, and optoelectronic fields. The results indicate that this biogenic method can serve as a sustainable proposal to produce nanostructured materials with diverse applications in the medical and environmental fields, such as eliminating pathogenic bacteria and purifying contaminated environments. Overall, this study significantly contributes to the development of sustainable nanomaterials and opens up new perspectives on the use of ovalbumin protein in the synthesis of multifunctional nanostructured materials.

Zinc oxide reinforced composites are a promising class of materials with a wide range of potential applications. By combining ZnO with other materials, scientists and engineers can achieve advanced functionalities that go beyond the properties of the individual components. The article offers to researchers and specialists an organized and thoughtful overview on outlining the impacts of composites, emphasis on ZnO nanoparticles reinforced composites.

The sustainable valorization of marine shell waste as functional additives for geopolymer materials represents a promising strategy for developing multifunctional materials for environmental remediation. In this study, metakaolin-based geopolymers were modified with calcium-rich particles obtained by calcination of five marine shell species (Chamelea gallina, Mya arenaria, Mytilus edulis, Pecten maximus, and Rapana venosa) under identical synthesis conditions to evaluate the influence of shell mineralogy on the structural, textural, adsorption, and antibacterial properties of the resulting composites. The materials were comprehensively characterized by Fourier transform infrared spectroscopy in attenuated total reflectance (ATR-FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption–desorption (BET/BJH) analyses. Functional performance was assessed through methylene blue (MB) adsorption experiments, adsorption kinetic modeling, and antibacterial tests against Escherichia coli (E. coli). ATR-FTIR and XRD analyses confirmed the formation of a stable amorphous geopolymer network containing residual crystalline phases together with shell-derived calcium carbonate, predominantly as calcite or aragonite depending on shell origin. The incorporation of shell-derived particles modified the pore architecture of the geopolymers. GP-SJ exhibited the highest BET specific surface area (94.30 m² g⁻¹) and the most developed mesoporous structure. Among the investigated formulations, GP-RP showed the most favorable overall combination of functional properties under the investigated conditions, exhibiting the highest methylene blue removal efficiency (63.97%) and experimental adsorption capacity at 160 min (9.60 mg g⁻¹), together with a comparatively high reduction in recoverable E. coli colonies during preliminary antibacterial screening. The combined structural and functional analyses demonstrate that the environmental performance of shell-modified geopolymers cannot be predicted from a single parameter such as BET surface area or calcium content alone, but results from the synergistic interaction between mineralogical composition, particle dispersion, pore accessibility, and matrix compactness. Under the investigated conditions, these findings provide evidence for proposed structure–property correlations under the investigated conditions and suggests that shell-derived calcium particles act as microstructural regulators of geopolymer matrices, providing a basis for the further development of sustainable multifunctional materials for simultaneous dye removal and bacterial reduction in wastewater treatment.

Hen eggshell is an abundant, calcite-rich food waste that is usually valorised by calcination at 800–1000 °C, an energy-intensive step that releases its carbonate CO₂ and destroys its biogenic microstructure. Low-temperature routes that keep the calcite intact have received little attention, and their effect on the structure and functions of geopolymer gels is unknown. This work examined whether eggshell conditioned at only 250 °C (ES-250) can replace 10 wt% of the metakaolin in a geopolymer gel, and what it changes. ES-250 remained pure biogenic calcite, with intracrystalline vesicles and residual organic matter, and the route needs ≈3–6 times less heat than calcination, including drying. In the hardened binder, ES-250 persisted as discrete 2–5 µm calcite particles without detectable Ca diffusion into the aluminosilicate gel. The Si–O–T bonding, the total pore volume and the N₂-accessible porosity (≈41%) were preserved, and only the BET surface area decreased (36.2 → 31.6 m² g⁻¹). Dye uptake in the dark was maintained, but the strong antibacterial effect of the plain geopolymer, which left no culturable Escherichia coli after 4 h, was largely lost (22–34% reduction). Low-temperature-conditioned eggshell is therefore a decarbonation-free, structurally inert filler for geopolymer gels, but not a functional additive.