Electrospun porous Fe 2 O 3 nanotubes as counter electrodes for dye‐sensitized solar cells

Porous Fe2O3 nanostructures were synthesized through electrospinning of Fe (NO3)3/polyvinylpyrrolidone followed by calcination in air. The morphology of the resultant Fe2O3 was tuned by changing the ratio between Fe (NO3)3 and the polymer matrix. The performance of these nanostructures as counter electrodes in dye-sensitized solar cells (DSSCs) was investigated. It was found that nanotubes exhibit significantly higher catalytic efficiency toward reducing I−/I3− electrolytes than nanorods and nanobelts, showing a photoelectric conversion efficiency of 4.0%, also superior to a range of transition metal oxides. Furthermore, the nanotube-based counter electrode showed lower resistance than other Fe2O3 nanostructures. These results were attributed to the high specific surface area (90.2 m2 g−1) of the nanotubes, which provides a large reaction site and can promote the charge transfer at the electrode/electrolyte interfaces. The low cost and ease of mass production make Fe2O3 nanotube a promising candidate to replace Pt as the counter electrode in DSSCs.