Synthesis of nanotitania decorated few-layer graphene for enhanced visible light driven photocatalysis

Reny Thankam Thomas; P Abdul Rasheed; N Sandhyarani

doi:10.1016/j.jcis.2014.04.054

Synthesis of nanotitania decorated few-layer graphene for enhanced visible light driven photocatalysis

J Colloid Interface Sci. 2014 Aug 15:428:214-21. doi: 10.1016/j.jcis.2014.04.054. Epub 2014 May 2.

Authors

Reny Thankam Thomas¹, P Abdul Rasheed¹, N Sandhyarani²

Affiliations

¹ Nanoscience Research Laboratory, School of Nano Science and Technology, National Institute of Technology, Calicut, Kerala 673 601, India.
² Nanoscience Research Laboratory, School of Nano Science and Technology, National Institute of Technology, Calicut, Kerala 673 601, India. Electronic address: sandhya@nitc.ac.in.

PMID: 24910056
DOI: 10.1016/j.jcis.2014.04.054

Abstract

We report a simple method for decorating carboxyl functionalized few-layer graphene with titania (TiO2) nanoparticles by sonication and stirring under room temperature. The nanocomposites showed a remarkable improvement in visible light driven photocatalysis. From Raman and XRD analysis the number of layers of graphene was found to be 3. The TiO2 decorated few-layer graphene (FLG) sheets were characterized by electron microscopy, Raman spectroscopy, infrared spectroscopy, XRD and UV-vis spectroscopy. Titania nanoparticles were uniformly decorated on FLG matrix. The incorporation of titania on FLG enhanced the visible light photocatalytic activity of titania, lowered the electron hole recombination and improved the electron hole mobility. The enhanced life time of the charge carriers was confirmed from the photocurrent measurements. Compared to bare TiO2 nanoparticles the FLG-TiO2 nanocomposites exhibited rapid degradation of Rhodamine B (Rhd B) under solar radiation. It was found that adsorption of dye molecules and the rate of degradation have been greatly enhanced in the FLG decorated with TiO2. The rapid degradation of Rhd B using carboxyl functionalized FLG-TiO2 within 8 min under solar radiation and 20 min under 30 W UV tube with very low concentration (0.01 wt.%) of the photocatalyst is the highlight of the present report. The mechanism of degradation and charge separation ability of the nanocomposite are also explored.

Keywords: Graphene; Nanocomposite; Photocatalytic degradation; Photocurrent; Rhodamine B; Titania; Visible light driven photocatalysis.