A comparative review of graphene oxide and TiO2 as photocataysts in photocatalytic systems.pdf

P. Sheath, M. Majumder A COMPARATIVE REVIEW OF GRAPHENE OXIDE AND TITANIUM DIOXIDE AS PHOTOCATALYSTS IN PHOTOCATALYTIC SYSTEMS Phillip Sheath 1 , Mainak Majumder 1 Nanoscale Science and Engineering Laboratory (NSEL) Monash University, Department of Mechanical Aerospace Engineering Wellington Rd, Clayton, Victoria, AUSTRALIA, 3800 E-mail: phillip.sheath@ ABSTRACT Commercially available TiO2 photocatalyst is the material of choice for photocatalysis. Recently graphene oxide (GO) has been found to have a bandgap tunable to its level of oxidation and amenable to a range of chemistries making GO highly versatile. GO is emerging as a material which can be modified for photocatalyst applications having recently been utilised for water splitting with encouraging results and dye degradation reactions with enhanced activity compared to TiO2. Herein TiO2 photocatalytic properties are compared to those of GO and GO-based systems. INTRODUCTION Photocatalysis is an extremely active area of research due to its large application space and the possibility to harness solar radiation, which is a readily available and abundant source of energy. Emerging and established applications include degradation of water borne contaminants, CO2 conversion to organic fuels such as methanol and production of H2 by water splitting for use as renewable fuel. Whilst vast arrays of photocatalyst materials have been investigated, TiO2 and its modifications are the most prevalent and the most studied. Although many properties of TiO2 make it among the best current candidates for photocatalysis, significant limitations regarding its efficiency have prevented photocatalysis to be a widespread technological platform. Progress to maximise the usefulness of TiO2 has been very slow, indicating that an alternative photocatalyst system is worth considering. Recently, a new material, graphene oxide (GO), has demonstrated promising photocatalytic ability (Yeh et al., 2010). Gr