Fabrication And Characterization Of Efficient Hybrid Photocatalysts Based On Titania And Graphene For Acid Orange Seven Dye Degradation Under UV Irradiation
P. Muthirulan, C. K. N. Devi, M. M. Sundaram
Volume 5, Issue 4, Page 163-171, Year 2014 | DOI: 10.5185/amlett.2013.7507
TiO2-GR nanocomposites; hybrid photocatalyst; acid orange 7; UV irradiation; photocatalysis.
Simple and proficient methodology has been proposed for the preparation of hybrid photocatalyst based on titanium dioxide (TiO2)-graphene (GR) nanocomposite for acid orange 7 (AO7) dye degradation under UV irradiation. High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy (SEM) studies revealed that TiO2 nanoparticles were uniformly dispersed on GR surface. TiO2-GR hybrid nanocomposite has also been characterized by Ultraviolet Diffusive Reflectance Spectroscopy (UV-DRS), Raman spectroscopy and X-ray diffraction (XRD) studies. Electrochemical Impedance spectroscopy (EIS) measurement revealed that the incorporation of GR with TiO2 nanoparticles significantly enhanced the electrical conductivity.The peak intensity of PL spectra of GR containing catalysts are lower than that of pristine TiO2, indicating that the electron–hole recombination rate of self-trapped excitations in TiO2 is reduced by the introduction of GR. The photocatalytic degradation measurements demonstrated that the TiO2-GR composites exhibited an enhanced photocatalytic activity for AO7 degradationunder UV irradiation compared to pure TiO2. This may due to greater adsorptivity ofdyes, extended light absorption and increased charge separation efficiency due to excellent electricalproperties of graphene and the large surface contact between graphene and TiO2 nanoparticles. Therefore, the TiO2-GR composites can be widely used as a ternary composite photocatalyst for treating the organic contaminant in the field of environmental protection. Copyright © 2014 VBRI press.