Titania nanofiber photoanodes for dye-sensitized solar cells

The porous structure of electrospun TiO2 nanofibers was characterized in-depth and the best performing nanofiber structure for application in dye sensitized solar cell was identified. Four types of TiO 2 nanofibers were investigated (electrospun from polyvinylpyrrolidone (PVP) and hydroxypropylcellulose (HPC) as templates) with diameters 100-280 nm and surface areas 9-100 m2/g. Mesoporous TiO2 films were prepared by supramolecular templating with a block copolymer Pluronic P123. For the preparation of composite nanofiber mesoporous films, 2% or 15% of electrospun nanofibers were added. Incorporation of nanofibers into the mesoporous film results in a decrease in dye N719 adsorption but at the same time in an increase of roughness factor. Solar efficiency of composite mesoporous films increases (unlike for pure mesoporous films) even for layer thickness higher than 2.3 μm. Thus we developed a simplified method for the preparation of thick mesoporous nanofiber electrodes with improved solar efficiency of 5.51% which outperforms that of pure mesoporous film (4.96%). © 2013 Elsevier B.V.