Lanthanum doped–TiO2 decorated on graphene oxide nanocomposite: A photocatalyst for enhanced degradation of acid blue 40 under simulated solar light 

¹Department of Applied Chemistry, University of Johannesburg, P.O. Box 17011, Doornfontein campus,  Johannesburg, 2028, South Africa

²Vinoba Bhave Research Institute, Sirsa Road, Saidabad, Allahabad, 221508, India

Adv. Mater. Lett., 2017, 8 (3), pp 295-302

DOI: 10.5185/amlett.2017.6826

Publication Date (Web): Jan 28, 2017

Copyright © IAAM-VBRI Press

E-mail: samkello2002@yahoo.com; pennyg@uj.ac.za

Abstract

La-TiO₂-GO nanocomposites were successfully synthesised via sol-gel method. Structures, morphologies and photocatalytic activities of the as-synthesized nanocomposites were determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy (RS) and scanning electron microscopy (SEM). UV-Vis diffuse reflectance spectroscopy was used to estimate band gap energies. The photocatalytic activities of the as-synthesized nanocomposites were evaluated for the degradation of Acid Blue 40 in aqueous solutions under simulated solar light. The photocatalytic results show that the as-synthesized La-doped TiO₂-GO (0.3% La) nanocomposite shows good photocatalytic activity and can be considered as a promising photocatalyst for the degradation of organic pollutants in water. The good photocatalytic efficiency is ascribed to the cooperative effect of improved visible light absorbance and separation of charge carriers due to the combined effect of La and the GO in the composite. Analysis from Total organic carbon (TOC) shows a high degree of complete mineralisation of Acid Blue 40 (TOC removal of 75%) which decreases the formation of possible degradation by-products. Due to the stability of La-TiO₂-GO (0.3% La) nanocomposite, it was reused for five times reaching 84.0% maximum degradation efficiency during the five cycles.

Keywords

Lanthanide, nanocomposite, graphene oxide, photocatalyst, acid blue 40, dye removal.