Electrospun porous Fe2O3 nanotubes as counter electrodes for dye-sensitized solar cells

Summary Porous Fe 2 O 3 nanostructures were synthesized through electrospinning of Fe (NO 3 ) 3 /polyvinylpyrrolidone followed by calcination in air. The morphology of the resultant Fe 2 O 3 was tuned by changing the ratio between Fe (NO 3 ) 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 − /I 3 − 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 Fe 2 O 3 nanostructures. These results were attributed to the high specific surface area (90.2 m 2 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 Fe 2 O 3 nanotube a promising candidate to replace Pt as the counter electrode in DSSCs.