The Fabrication of Titanium Dioxide-Tin Oxide/Reduced Graphene Oxide Photoanodes for Dye-Sensitized Solar Cells

Abstract

This research studied the preparation of titanium dioxide (TiO2) composite films with the incorporation of tin oxide and reduced graphene oxide (SnO2-RGO) for uses as photoanodes in dye-sensitized solar cells (DSSCs). The experimental procedure started with the synthesis of graphene oxide by Hummer's method, followed by the preparation of SnO2-RGO composite materials by hydrothermal process. The resultant SnO2-RGO was sequentially mixed with TiO2 to prepare the composite films by doctor-blade method. The results indicated that the addition of graphene oxide into SnO2 could reduce the band gap, avoid the agglomeration, and improve the dispersion of tin oxide particles (SnO2). According to the efficiency tests of the obtained photoanodes, a small amount of RGO could significantly affect the DSSC’s performance. Without RGO, TiO2-SnO2 photoanodes exhibited very poor performance. This could be due to low dye-adsorption capability and low electron transfer ability. The addition of excess amount of RGO in photoanode could, however, lead to negative effects such as charge trapping and lower solar cell efficiency.