Non-Thermal Plasma Synthesis of TiO_۲ Nanoparticles for Environmental Applications: Adsorption Studies

The increasing prevalence of pharmaceutical contaminants in aquatic environments, particularly antibiotics, poses serious ecological risks and contributes to the spread of antibiotic-resistant bacteria. Conventional wastewater treatment processes are insufficient for removing these persistent pollutants. Titanium dioxide (TiO₂) nanoparticles, owing to their high surface area, adsorption capacity, and antibacterial properties, offer a promising solution. This study investigates the synthesis of TiO₂ nanoparticles via a Non-Thermal Plasma (NTP) method and evaluates their multifunctional performance for environmental remediation. TiO₂ nanoparticles were synthesized from titanium tetrachloride under ambient temperature and atmospheric pressure using N₂/Ar plasma for ۲۵ min. Nanoparticles were characterized by FESEM, EFTEM, DLS, zeta potential, XRD, FT-IR, UV–Vis, TGA/DTG, and nitrogen adsorption–desorption analysis. Adsorption studies used methyl orange and antibiotics (amoxicillin, ampicillin, and doripenem), with Langmuir, Freundlich, and Toth isotherms modeling adsorption behavior. Antibacterial activity was assessed against Escherichia coli and Staphylococcus epidermidis. TiO₂ nanoparticles displayed a mean size of ۲۵.۲ ± ۴.۵۳ nm (FESEM), high crystallinity (anatase, ۱۳.۶ nm), a surface area of ۱۱۲.۴ m²/g, and mesoporosity (~۱۰ nm pores). Zeta potential (−۳۹ mV) indicated colloidal stability. TGA showed minimal weight loss above ۵۰۰ °C, with major loss (۴۰۰–۴۵۰ °C) due to surface-bound organics. Methyl orange adsorption exceeded ۸۰% under optimal conditions, and antibiotic removal followed Langmuir/Toth isotherms, with doripenem showing the highest affinity. MIC values were ~۰.۱۲۴ mg/mL for both bacterial strains. Plasma-assisted TiO₂ nanoparticles integrate high crystallinity, mesoporosity, adsorption efficiency, and antibacterial activity, providing a scalable, sustainable strategy for simultaneous removal of dyes and antibiotics, with significant potential to mitigate pharmaceutical pollution and antibiotic resistance.

کلیدواژه ها:

Plasma-assisted synthesis ، Anatase TiO₂ nanoparticles ، Antibacterial activity ، Adsorption of dyes and antibiotics ، Mesoporous nanomaterials ، Wastewater treatment