Integrating Graphene and C_(60) Into TiO2 Nanofibers via Electrospinning Process for Enhanced Conversion Efficiencies of DSSCs

摘要

Electrospun TiO2 nanofibers incorporated with graphene and C_(60) nanoparticles at 0, 1, 2, 4, and 8wt.% were produced using poly (vinyle acetate), dimetylfomamide, and titanium (IV) isopropoxide. The resultant nanofibers were heat treated at 300 ° C for 2 hrs in a standard oven to remove all the organic parts of the nanofibers, and then further heated up to 500 ° C in Ar for additional 12 hrs to crystallize the TiO2 nanofibers. For the graphene and C60 containing nanofibers, two steps annealing at 300 ° C (air) and 500 ° C (Ar) were conducted to eliminate the decomposition processes of the graphene and C_(60) in the TiO2 nanofibers. SEM, TEM and XRD studies were conducted on the samples. The results showed that graphene and C_(60) were well integrated in the nanofiber structures. The TiO2 nanofibers with the inclusions were mixed in a solution to form a paste, which was then applied on a conductive glass after the TiCl4 solution treatments to make various dye sensitized solar cells (DSSCs). This technique enables creation of solar cells with variable thicknesses of 7 mmto45 mm. The effects of the manufacturing technique, thickness of the paste, different percentages of graphene and C_(60) nanoparticles on overall efficiency of the solar cell were studied in detail. The test studies indicated that in the presence of graphene and C_(60) , the DSSC efficiency increased more than 50%. The present study may guide some of the scientists and engineers to tailor the energy band gap structures of the semiconductor materials for different industrial applications, including DSSCs, as well as water splitting, catalyst, Li-ion batteries, and fuel cells.