Thermodynamic and kinetics studies of Methylene Blue Adsorption onto Synthesised TiO2 Cellulose Acetate Nanocomposite in Aqueous Medium

Synthesis and characterization of a titanium dioxide–cellulose acetate (TiO₂–CA) nanocomposite was carried out for the removal of methylene blue (MB) dye from aqueous media. The thermodynamic and kinetic properties of the adsorption were studied. The nanocomposite was prepared through a simple sol–gel–assisted blending route using titanium isopropoxide as the TiO₂ precursor and cellulose acetate as the biodegradable polymer matrix. The synthesized material was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to confirm functional group interactions and morphological features. Adsorption experiments were carried out under varying operational parameters, including pH, initial dye concentration, contact time, and adsorbent dosage. The maximum removal efficiency occurred at pH 6, with equilibrium reached within 90 minutes. The adsorption process followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating monolayer adsorption with chemisorptive interaction. The TiO₂–CA nanocomposite demonstrated enhanced dye removal compared to pure cellulose acetate, attributed to synergistic binding and photocatalytic surface activity. The study highlights a sustainable, low-cost, and efficient approach to wastewater remediation using a biodegradable inorganic hybrid nanomaterial.