Solar light induced photodegradation of oxytetracyline using Zr doped TiO2/CaO based nanocomposite

Abstract

Zr doped TiO₂/CaO (Zr-TiO₂/CaO) has been synthesized by sol-gel method and its photocatalytic activity tested for the removal of oxytetracycline (OTC) from aqueous solution. Zr-TiO₂/CaO has been characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy diffraction X-ray, Fourier transform infrared spectroscopy and UV-visible spectral analysis. SEM results confirm the dispersion of Zr doped TiO₂ on calcium oxide support. The Zr-TiO₂/CaO nanocomposite exhibits semicrystalline structure with average size of 50 nm. The photocatalytic activity of Zr-TiO₂/CaO has been evaluated for the photodegradation of OTC under solar light. The synergetic adsorption and photocatalysis (A+P) is most efficient for oxytetracycline removal. The effect of various reaction parameters such as OTC concentration, pH of reaction solution and catalyst loading has been evaluated for OTC degradation. The photocatalytic degradation of oxytetracycline obeys pseudo-first order kinetics. The nanocomposite exhibits significant recyclability due to easy separation and stability in the reaction solution. The oxidative removal occurrs through hydroxyl radical formation. The nanocomposite displays excellent photocatalytic property for degradation of oxytetracycline and may have potential applications in water treatment.