Mechanochemical Synthesis, Structural Characterization and Visible Light Photocatalysis of TiO2/ZnFe2O4 Nnanocomposites

Abstract

ABSTRACTNanocomposite heterogeneous semiconductors with suitable energy levels (gaps) are exhibiting excellent photocatalytic properties under visible light irradiation. TiO2/ZnFe2O4 has been selected among different alloys because of (i) its low band gap ∼1.9 eV (ii) the nontoxicity of ZnFe2O4 (iii) visible light absorption characteristics of ZnFe2O4 due to its narrow band gap and (iv) not being susceptible to photoanodic corrosion. A mechanochemical synthesis approach using high energy milling is employed to prepare TiO2/ZnFe2O4 under different experimental parameters and conditions. The effects of ball milling and calcination on the photocatalytic behavior of TiO2 and TiO2/ZnFe2O4 have been determined. The as-milled nanocomposite materials are characterized with PXD, SEM and EDS procedures. The photocatalytic activity of TiO2/ZnFe2O4 nanocomposites for the photodegradation of phenol under visible light irradiation has been studied systematically by UV-Vis spectrometer. It is interesting to note a red shift of 0.25 eV in the absorption edge of the ball-milled TiO2 sample when compared to the non ball milled TiO2 photocatalyst.