Investigating the Performance of the Graphene-WO3-TiO2 Ternary Composite in Dye-Sensitized Solar Cells

A hydrothermal method was used to synthesize different photoanodes for their application in dye-sensitized solar cells (DSSC). These photoanodes included WO3, TiO2, Graphene-TiO2, WO3-TiO2, and a nanostructure of Graphene-WO3-TiO2. The morphology of the nanoparticles was analyzed using the scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-vis), and Fourier-transform infrared spectroscopy (FTIR). The results demonstrated that the graphene-WO3-TiO2 nanostructure had a large surface area, having provided more active sites for the efficient conversion of solar energy.  Notably, the DSSC incorporating the graphene-WO3-TiO2 nanoparticle electrode outperformed cells based solely on TiO2 and WO3, achieving a higher short-circuit current density of 7.5 mA.cm-2, an open-circuit voltage of 0.68 V, a fill factor of 0.46, and a power conversion efficiency of 2.4%. In contrast, the pure TiO2 and WO3 cells only achieved efficiencies of 0.88% and 0.69% Respectively.  The excellent electron mobility of the ternary nanostructure facilitated the charge trapping and injection into the conductive substrate, reducing recombination. Additionally, the scattering effect of the WO3 nanorods and graphene enhanced the light harvesting in the photoanode, leading to an increase in the overall efficiency of the solar cell. These findings highlight the potential of the synthesized graphene-WO3-TiO2 nanostructure as a promising photoanode material to be applied in DSSC.