Abstract

This work describes the preparation of chitosan/poly (vinyl alcohol)/titanium dioxide (CS/PVA/TiO2) nanocomposite for its use as a photocatalyst under visible light irradiation. The prepared nanocomposite was characterized by Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic activity of CS/PVA/TiO2 was evaluated by photocatalytic removal of acid red 14 (AR14) in aqueous solution as a model pollutant. A Taguchi orthogonal array experimental design with an L16 matrix was employed to optimize the factors affecting the photocatalytic efficiency of CS/PVA/TiO2 nanocomposite such as: pH, irradiation time, initial dye concentration, and nanocomposite dosage. The optimum conditions were found to be as follows: pH = 3; irradiation time = 120 min; initial dye concentration = 10 mg L−1, and nanocomposite dosage = 400 mg L−1. The pH was found to be the most effective factor for dye removal, followed by the nanocomposite dosage. The dye removal during visible‐CS/PVA/TiO2 process under optimal conditions followed the pseudo‐first‐order reaction model with the rate constants of 0.0188 min−1. The photocatalytic activity of CS/PVA/TiO2 nanocomposite dropped very slightly in five consecutive reaction cycles.