Ecofriendly, green tea extract directed sol–gel synthesis of nano titania for photocatalytic application

Abstract

Biomaterial assisted green synthesis of metal oxide nanoparticles plays a vital role as an eco-friendly alternate to chemical templated approach, in enhancing the physico-chemical properties of the solids. Herein, we have reported the synthesis of mesoporous titania nanoparticles by sol–gel method with the assistance of green tea extract (GTE). The synthesized catalysts were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Thermo gravimetric (TG), Brunauer-Emmett-Teller (BET), diffused reflectance spectroscopy UV–Visible (DRS-UV), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) analyses. The resulting nano titania exhibited excellent mesoporosity with increased surface area compared to control nano titania as evidenced from BET analysis. XRD results showed that highly crystalline anatase titania nanoparticles could be derived through controlled hydrolysis. Green tea extract also aided in shifting the optical absorption edge of titania towards the visible light region and enabled nano titania to function as an efficient photocatalyst for the photodegradation of Congo red, a model organic pollutant, under solar irradiation. Green tea extract was proved to be a suitable template for the synthesis of visible light active titania with good crystallite characteristics. Hence, it could be proposed as an environmentally benign alternate to the chemical templates for the sol–gel synthesis of titania nanoparticles.