Probing the role of thermally reduced graphene oxide in enhancing performance of TiO2 in photocatalytic phenol removal from aqueous environments

• One-pot syntheses of titania graphene oxide (GO) and titania thermally reduced graphene oxide (TGO) composites.
• Enhanced photocatalytic behaviour of composites with respect to titania.
• Improved adsorption and reduced hole/electron recombination rates for composites.
• Reaction under nitrogen shows TGO to acts in electron transport and storage.

A simple one-pot syntheses of TiO2-graphene oxide (GO)/thermally reduced graphene oxide (TGO) composites were performed with different concentrations of GO/TGO (0.25, 0.5 and 1.0 wt%). The materials were characterised by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and nitrogen adsorption–desorption isotherms in order to evaluate structural and physiochemical properties of synthesised materials. The TiO2-0.25% TGO exhibited the highest photocatalytic activity for phenol degradation in aqueous solution and this was attributed to optimal adsorption efficiency of phenol along with prolonged lifetime of electron–hole pairs. Photocatalytic activity in the absence of dissolved oxygen (under nitrogen) was also performed and, in the case of TGO, confirmed the role of graphene as an electron sink and transporter for suppression of electron–hole pair recombination.

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