Photovoltaic performance and photocatalytic activity of facile synthesized graphene decorated TiO₂ monohybrid using nanosecond pulsed ablation in liquid technique

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.