Role of graphene oxide/yttrium oxide nanocomposites as a cathode material for natural dye‐sensitized solar cell applications

Abstract

Natural dye-sensitized solar cells (DSSCs) are becoming promising candidates for replacing synthetic dyes. Graphene oxide is prepared from natural graphite flakes by modified Hummers method. A novel graphene oxide/yttrium oxide (GO/Y 2 O 3 ) nanocomposites are prepared by chemical precipitation method. The different concentration of (5:1, 5:2, and 5:3) of yttrium oxide nanoparticles exaggerated on the surface of graphene oxide nanosheets. The prepared nanocomposites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDAX), Fourier transform infrared spectroscopy (FT-IR), Raman scattering spectroscopy and ultravioletvisible (UV-vis) absorption spectroscopy. The XRD analysis showed that the crystallite size of the GO/Y 2 O 3 (5:1, 5:2, and 5:3) is found to be around 23, 25.2, and 26.92 nm. Field emission scanning electron microscopy (FE-SEM) revealed that the flakes like shaped yttrium oxide nanoparticles are uniformly dispersed on the surface of GO sheets. The UV-vis studies showed that the prepared Jasminoum grandiflorum L (JG) dye belongs to chlorophyll group with the absorption of 4.2 eV. The electrochemical activity of the prepared nanocomposites is investigated by cyclic voltammetry (CV) technique. The power conversion efficiency of prepared sandwich type DSSCs (5:3) is found to be 1.67%.

Theoretical study on dye-sensitized solar cells using graphene quantum dot and curcumin, pahthalocyanine dyes

“…As the energy gap is the driving force for the electron transfer, the nanocomposite has large energy gap which is favorable since it can give larger driving force for the electron transfer. In Table 1, we can find that the energy gap of the GQD/Pc nanocomposite equal to 3.102 eV, which implies that the driving force of the nanocomposite is suitable for the electron transfer [34]. UV-Visible spectra for nanostructures are investigated by using time dependent density functional theory (TD-DFT) with B3LYP/6-31G level, and presented in Figure 4.…”