Abstract
We report the synthesis of graphene-TiO2 nanohybrid catalyst using different concentrations of deionized water suspended in graphene sheet as a medium in the ablation of titanium dioxide (TiO2) nanoparticles using an one-step pulsed laser ablation in liquid setup equipped with Nd-YAG laser (532 nm wavelength) which was kept at a laser fluence of 320 mJ/pulse, a pulse duration of 6 ns and a frequency of 10 Hz. The produced graphene-TiO2 nanohybrids obtained is active in both the ultraviolet and visible spectral regions as explained in the UV-vis absorption spectroscopy. This property is affiliated with improved crystallinity as shown in the X-ray diffraction technique and Raman spectroscopy. A perfect interaction between TiO2 nanoparticles and graphene sheets is confirmed by the bond formed between the surface carbon of graphene and oxygen in TiO2, which was obtained in the Fourier transform infrared analysis, Raman spectroscopy and X-ray photoelectron spectroscopy analysis. This is also confirmed with the morphology obtained from the transmission electron microscopic image of the nanohybrid. The prepared graphene-TiO2 nanohybrids were utilized as photo-catalyst and photo-anode in the degradation of methyl orange dye and dye sensitized solar cell, respectively. Improved crystallinity and reduced charge transfer resistance was observed in TiO2 nanoparticles hybridized with 3% graphene. This leads to an improvement in the photo-conversion efficiency of the dye sensitized solar cell from 0.60% to 3.80% and an enhancement in the removal of methyl orange pollutant from 89.10% to 99.60% when degraded under UV-vis solar spectrum. (C) 2016 Elsevier Ltd. All rights reserved.