Green-Synthesized Titanium Dioxide Nanoparticles for Photocatalytic Degradation of Textile Dye Effluents

Abstract

Textile industries discharge large volumes of dye-containing effluents, causing significant environmental pollution. In this study, titanium dioxide nanoparticles (TiO₂ NPs) were synthesized using Azadirachta indica (neem) leaf extract as a reducing and stabilizing agent. The green-synthesized TiO₂ NPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Vis spectroscopy, and Fourier-transform infrared (FTIR) analysis. Photocatalytic activity was evaluated against methylene blue (MB) and rhodamine B (RhB) under simulated solar irradiation. The nanoparticles exhibited an average crystalline size of ~18 nm and a band gap of 3.1 eV. Photocatalytic experiments demonstrated >95% degradation of MB within 120 min and ~90% degradation of RhB within 150 min. Kinetic modeling followed pseudo-first-order behavior. Reusability studies confirmed stable catalytic activity after five cycles, while toxicity assays indicated reduced cytotoxicity of treated effluents. These findings highlight the potential of green-synthesized TiO₂ nanoparticles for sustainable wastewater remediation.