Characterization of reduced graphene oxide/macrocyclic Fe(II) complex nanocomposite as the counter electrode in Pt-free dye-sensitized solar cells

Abstract

In this study, we have developed a composite material by using graphene oxide (GO) and a macrocyclic Fe metal complex as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). Different ratios of GO and macrocyclic metal complex have been used and analyzed using various characterization techniques (field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy). These results showed that there is complete reaction between GO and macrocyclic Fe complex and the macrocyclic complex has been grafted evenly onto the surface of graphene. Electrochemical catalytic capacity of the CE’s has been enhanced due to the redox capacity of the macrocyclic metal complex, high surface area and high conduction of graphene. This CE undergoes various studies (current density-voltage, incident photo-to-current conversion efficiency, and electrochemical impedance spectroscopy) and results have been compared with that of conventional platinum CE. CE’s made of GO and macrocyclic Fe complex show better efficiency compared to the traditional platinum counter electrode. Thus, this composite material can be used as a CE for the DSSC because of its less cost and excellent performance. It is an ideal replacement for the expensive platinum CE.