Eco-friendly synthesis of TiO ₂ nanomaterials via cold nitrogen plasma: Optical, electrical and biological evaluations

In this work, titanium dioxide nanoparticles were prepared using plasma jetting. A key feature of this work is its reliance on a simple and environmentally friendly method based on nitrogen gas plasma, without the addition of any chemicals or heating. This results in stable nanoparticles that retain their original structure, allowing them to exhibit important properties and making them effective for gas detection. The resulting material was characterized using various techniques, including EDX, AFM, DLS-Zeta, UV–Vis, FTIR, Raman and PL. X-ray diffraction results showed that the nanoparticles possess a pure anatase phase with an average crystalline size of 18[Formula: see text]mm. The study also demonstrated the formation of uniform and dispersed nanoparticles with high surface roughness, while spectroscopic analysis revealed a low energy gap of approximately 3.2[Formula: see text]eV. The sensor based on these particles exhibited high sensitivity to NO 2 gas, with a high response rate and short response times at 250 ∘ C. Microbiological testing also demonstrated biological activity against Staphylococcus aureus and Escherichia coli, with inhibition diameters reaching 35[Formula: see text]mm and 31[Formula: see text]mm, respectively. These results confirm that nitrogen-based cold plasma technology is a promising method for preparing multifunctional nanomaterials that combine optical, electrical and biological properties, making them suitable for future environmental and medical applications.