Energy
N. Gilani; S. Fallahdoost Moghadam; Ali Akbar Y.
Abstract
A hydrothermal method was used to synthesize different photoanodes for dye-sensitized solar cell (DSSC) applications. These photoanodes included WO3, TiO2, Graphene-TiO2, WO3-TiO2, and a nanostructure of Graphene-WO3-TiO2. The morphology of the nanoparticles was analyzed using scanning electron microscopy ...
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A hydrothermal method was used to synthesize different photoanodes for dye-sensitized solar cell (DSSC) applications. These photoanodes included WO3, TiO2, Graphene-TiO2, WO3-TiO2, and a nanostructure of Graphene-WO3-TiO2. The morphology of the nanoparticles was analyzed using 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, providing more active sites for efficient conversion of solar energy. Notably, the DSSC incorporating the graphene-WO3-TiO2 nanoparticles 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 an efficiency of 0.88% and 0.69%, Respectively. The excellent electron mobility of the ternary nanostructure facilitated charge trapping and injection into the conductive substrate, reducing recombination. Additionally, the scattering effect of the WO3 nanorods and graphene enhanced light harvesting in the photoanode, leading to an increase in overall solar cell efficiency. These findings highlight the potential of the synthesized graphene-WO3-TiO2 nanostructure as a promising photoanode material for DSSC applications.
Materials synthesize and production
A. Hadi; J. Karimi-Sabet; S. M. A. Moosavian; S. Ghorbanian
Volume 12, Issue 4 , October 2015, , Pages 52-68
Abstract
After fullerene and nanotubes, graphene is a new allotrope of carbon. This attractive nanomaterial can be produced by different methods. In this work, we have used the less common approach for preparation of graphene. This technique is based on the utilization of supercritical fluid. Ethanol was used ...
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After fullerene and nanotubes, graphene is a new allotrope of carbon. This attractive nanomaterial can be produced by different methods. In this work, we have used the less common approach for preparation of graphene. This technique is based on the utilization of supercritical fluid. Ethanol was used as the solvent for exfoliation of pristine graphite, at the temperature of 400 oC and pressure of 40 MPa. In addition, supercritical ethanol was used to reduce and exfoliate graphite oxide. FT-IR spectra indicate that reduction and exfoliation of graphite oxide can be done in supercritical ethanol, simultaneously. Effect of graphite oxidation on the yield and quality of graphene was investigated and results showed that oxidation of graphite can improve the yield of supercritical process from 12.5% to 26.8%, but Raman spectra revealed that quality of graphene samples produced by graphite oxide is lower than neat graphite. Moreover, the impacts of initial graphite concentration and sonication power on the exfoliation yield were studied. Finally, hybrid structure of graphene and titanium dioxide nanoparticles were prepared by ultrasonic method and used for photocatalytic degradation of methylene blue dye pollutant. Results revealed that titanium dioxide nanoparticles show better photocatalytic performance in presence of graphene sheets.