We describe the use of highly ordered transparent TiO2 nanotube arrays in dye-sensitized solar cells (DSCs). Highly 46-nm pore diameter, 17-nm wall thickness, and 360-nm length were grown perpendicular to a fluorine-doped tin oxide-coated glass substrate by anodic oxidation titanium thin film. After crystallization an oxygen anneal, are treated with TiCl4 enhance photogenerated current then integrated into DSC structure using commercially available ruthenium-based dye. Although negative...

The past several decades have seen a significant rise in atmospheric carbon dioxide levels resulting from the combustion of hydrocarbon fuels. A solar energy based technology to recycle into readily transportable fuel (i.e., fuel) would help reduce CO2 and partly fulfill demands within present infrastructure. We review status conversion techniques, with particular attention recently developed photocatalytic process convert water vapor fuels using sunlight.

Single-crystal one-dimensional (1D) semiconductor architectures are important in materials-based applications requiring a large surface area, morphological control, and superior charge transport. Titania has widespread utility including photocatalysis, photochromism, photovoltaics, gas sensors. While considerable efforts have focused on the preparation of 1D TiO2, no methods been available to grow crystalline nanowire arrays directly onto transparent conducting oxide (TCO) substrates,...

In this study highly ordered titania nanotube arrays of variable wall thickness are used to photocleave water under ultraviolet irradiation. We demonstrate that the and length nanotubes can be controlled via anodization bath temperature. find is a key parameter influencing magnitude photoanodic response overall efficiency water-splitting reaction. For 22 nm inner pore diameter arrays, those fabricated in 5 degrees C bath, 224 34 produced was thrice array 50 120 9 wall-thickness. At high...

We report on a novel heterojunction WO(3)/BiVO(4) photoanode for photoelectrochemical water splitting. The films are prepared by solvothermal deposition of WO(3) nanorod-array film onto fluorine-doped tin oxide (FTO) coated glass, with subsequent low bandgap, 2.4 eV, visible light responding BiVO(4) layer spin-coating. structure offers enhanced photoconversion efficiency and increased photocorrosion stability. Compared to planar films, the show significantly improved properties due, we...

Efficient solar conversion of carbon dioxide and water vapor to methane other hydrocarbons is achieved using nitrogen-doped titania nanotube arrays, with a wall thickness low enough facilitate effective carrier transfer the adsorbing species, surface-loaded nanodimensional islands cocatalysts platinum and/or copper. All experiments are conducted in outdoor sunlight at University Park, PA. Intermediate reaction products, hydrogen monoxide, also detected their relative concentrations...

In this article, we present recent advances that have achieved toward improving the properties of anodically formed semiconducting TiO2 nanotubes as well nanowire arrays electrodes for oxidative photoelectrochemistry. The morphology, crystallinity, composition, and illumination geometry nanotube or are critical factors in their performance photoelectrodes. We discuss key aspects relating to each factor each. With respect more fully investigated arrays, ability control morphological...

The fabrication of highly-ordered TiO2 nanotube arrays up to 134 µm in length by anodization Ti foil has recently been reported (Paulose et al 2006 J. Phys. Chem. B 110 16179). This work reports an extension the technique achieve 220 length, with a length-to-outer diameter aspect ratio ≈1400, as well their initial application dye-sensitized solar cells and hydrogen production water photoelectrolysis. are fabricated potentiostatic fluoride ion containing baths combination non-aqueous organic...

Extremely sensitive, drift‐free, and robust hydrogen sensors based on titania nanotube arrays (see Figure) are reported. Very large changes in the electrical conductivity of nanotubes upon exposure to gas have been measured, over one order magnitude greater than previous record. Dependence both temperature pore size is found.

Highly ordered, vertically oriented TiO2 nanotube arrays fabricated by potentiostatic anodization of titanium constitute a material architecture that offers large internal surface area without concomitant decrease in geometric and structural order. The precisely nature the crystalline (after annealing) makes them excellent electron percolation pathways for vectorial charge transfer between interfaces. Herein are briefly considered their fabrication, as well initial application to hydrogen...

We report on the anodic formation of a self-standing 720 μm thick TiO2 nanotubular membrane by complete consumption 250 titanium foil sample. By employing double sided electrochemical oxidation in an electrolyte comprised water, NH4F, and ethylene glycol, we obtain two highly ordered, hexagonal close-packed titania nanotube arrays 360 length that are separated thin compact oxide layer; individual nanotubes each array have aspect ratio ∼2200. The potentiostatic anodization water dramatically...

Photocorrosion stable WO3 nanowire arrays are synthesized by a solvothermal technique on fluorine-doped tin oxide coated glass. morphologies of hexagonal and monoclinic structure, ranging from to nanoflake arrays, tailored adjusting solution composition with growth along the (001) direction. Photoelectrochemical measurements illustrative films show incident photon-to-current conversion efficiencies higher than 60% at 400 nm photocurrent 1.43 mA/cm2 under AM 1.5G illumination. Our film offers...

Titanium thin films, 400 nm to 1000 thick, fabricated by radio frequency (rf) sputter deposition are anodized in an electrolyte containing acetic acid and hydrofluoric form optically transparent films of highly ordered titania nanotube arrays. Real-time monitoring the anodization current, at a fixed potential, is used controllably eliminate Ti layer underneath titanium oxide array without disturbing architecture. Fabrication variables critical achieving nanotube-array film include annealing...

We report for the first time fabrication of self-aligned hexagonally closed-packed titania nanotube arrays over 1000 μm in length and aspect ratio ≈10 000 by potentiostatic anodization titanium. describe a process which such thick array films can be transformed into self-standing, flat or cylindrical, mechanically robust, polycrystalline TiO2 membranes precisely controlled nanoscale porosity. The self-standing are characterized using Brunauer−Emmett−Teller surface area measurements, glancing...