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TiO 2 nanowires with a diameter of ∼150 nm, length of ∼3-4 µm, and aspect ratio of 10:1, were prepared by ultrasonically dispersing electrospun continuous nanofibers in monocarboxylic acids. The resulting pastes were used for making nanowire films on conducting glass substrates with thicknesses in the range of 500 nm to 100 µm, good adhesion, and high nanowire packing. These films were used to fabricate dye-sensitized solar cells using the D131 dye and the iodide/triiodide electrolyte. Transient photocurrent measurements showed a high electron diffusion coefficient in those nanowire films. The measured diffusion coefficient in those TiO 2 nanowires was orders of magnitude higher than that observed in nanoparticles under similar experimental conditions. The charge-transport mechanism in the nanowire sample is discussed in support with the measured open-circuit voltage decay curves.

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Polyaniline nanofibers (PANI-NFs) web are fabricated by electrospinning and used as electrode materials for supercapacitors. Field-emission scanning electron microscope micrographs reveal nanofibers web were made up of high aspect ratio (>50) nanofibers of length $30 lm and average diameter $200 nm. Their electrochemical performance in aqueous (1M H 2 SO 4 and Na 2 SO 4 ) and organic (1M LiClO 4 in propylene carbonate) electrolytes is compared with PANI powder prepared by in situ chemical oxidative polymerization of aniline. The electrochemical properties of PANI-NFs web and PANI powder are studied using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. PANI-NFs web show higher specific capacitance ($267 F g À1 ) than chemically synthesized PANI powder ($208 F g À1 ) in 1M H 2 SO 4 . Further, PANI-NFs web demonstrated very stable and superior performance than its counterpart due to interconnected fibrous morphology facilitating the faster Faradic reaction toward electrolyte and delivered specific capacitance $230 F g À1 at 1000th cycle. Capacitance retention of PANI-NFs web (86%) is higher than that observed for PANI powder (48%) indicating the feasibility of electro spun PANI-NFs web as superior electrode materials for supercapacitors.