Green synthesis of Cu-doped TiO2 nanoparticles via Cannabis Sativa Leaves for efficient adsorption of cationic dyes from wastewater

In this study, 5 wt. %Cu-doped TiO₂ nanoparticles (NPs) were synthesized through a green and sustainable method, utilizing Cannabis sativa leaf extract as a reducing agent to promote eco-friendly wastewater treatment. The NPs were characterized using XRD, FESEM, BET, EDAX, and TEM, revealing uniform dispersion, an average particle size of approximately 20.5 nm, and a high surface area of 92 m²/g. These NPs were employed for adsorption of Methylene Blue (MB) and Rhodamine B (RhB) dyes from aqueous solutions at initial concentrations of 1–10 mg/L. Adsorption experiments, conducted over 150 min, showed equilibrium data best fitting the Freundlich isotherm (R² = 0.9979 for MB, 0.9995 for RhB), indicating multilayer adsorption. Kinetic studies confirmed that the Elovich models provided the best fit (R² > 0.997), suggesting chemisorption-dominated processes. The NPs exhibited high adsorption efficiency, offering a cost-effective and sustainable solution for treating textile wastewater, addressing critical environmental challenges posed by industrial dyes.