Abstract
The grape extract is a potential natural reducing agent because of its high phenolic content. The extracts of seeds, skin, and pulp of grape were prepared by digestion, grinding, and soxhlet methods and used for reducing graphene oxide (GO). The reduced GO made using the soxhlet extract of grape seed (GRGO) was hydrothermally treated with titanium dioxide (TiO(2)) for the synthesis of GRGO-TiO(2) nanocomposite. The X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), UV-vis, photoluminescence, and Raman spectra studies further confirmed the formation of GRGO and the GRGO-TiO(2) hybrid. Scanning electron microscope and transmission electron microscope studies showed the decoration of spherical TiO(2) particles (<100 nm) on the few-layered GRGO sheets. The GRGO-TiO(2) hybrid was explored as a working electrode for supercapacitors and visible light photocatalyst for water decontamination. GRGO-TiO(2) showed higher specific capacitance (175 F g(-1)) than GRGO (150 F g(-1)) and TiO(2) (125 F g(-1)) in an aqueous electrolyte. GRGO-TiO(2) exhibited 83.6% capacitance retention even after 2000 cycles, indicating the good stability of the material. Further, under visible light irradiation (λ > 400 nm), GRGO-TiO(2) showed ∼30% higher photo-oxidation of the bromophenol blue (BPB) dye than TiO(2). Also, GRGO-TiO(2) decreased the total organic carbon content of BPB from 92 to 18 ppm. Overall, the soxhlet extract of grape seed was found to be a cost-effective reducing agent for the preparation of GRGO, which is a suitable material to be used in supercapacitors and photocatalysis.