No abstract

Transparent conductors and charge transport layers play a key role in the design and fabrication of efficient renewable energy and electronic devices. Over the years, Indium tin oxide (ITO), is...

n-Type anatase-phase one-dimensional TiO2 nanostructure arrays coated with nanoparticles of Cu or CuPt have emerged as high performance photocatalysts for both photooxidation and photoreduction. The properties of the catalyst-promoter interface are recognized to be critical to this high performance but are largely unknown. Using X-ray and ultraviolet photoelectron spectroscopies (XPS/UPS), we probed the electronic properties of the CuPt-TiO2 interface in transparent TiO2 nanotube arrays (TTNTAs) coated with photodeposited CuPt nanoparticles (CuPt-TTNTA hybrids) as well as those coated with sputtered CuPt (Sput-CuPt-TTNTA hybrids). XPS and UPS spectra provided the evidence of a Schottky barrier with a band-bending of 0.49-0.67 eV at the CuPt-TiO2 interface in CuPt-TTNTA hybrids due to which photoexcited electrons are expected to be retained in the TiO2 while photoexcited holes will be collected by the CuPt nanoparticles. For Sput-CuPt-TTNTA hybrids, no such band-bending was observed. These results point to the importance of the metal nanoparticle preparation technique on interfacial band-alignments and challenge the conventional understanding of the promoting action of noble metal nanoparticles on TiO2 photocatalysts as sinks for photoexcited electrons.

No abstract

Rutile-phase TiO2 nanotube arrays without broken walls were formed by annealing of anodically formed nanotubes in a propane flame at 650 °C and in air at 750 °C. An unusual morphological transformation was observed from the ellipsoidal pore-shapes of titania nanotubes grown in aqueous electrolyte to a square-shaped pore structure subsequent to the anneals. 750 °C annealed nanotubes were found to be lightly p-type, rare in TiO2.

This study examines the Total Factor Productivity (TFP) growth of the preexisting units on a balanced sample for ten years (1998-1999 to 2007-2008) following the Levinsohn and Petrin (2003) technique. This study uses data from the Annual Survey of Industries at factory level. The results of the study indicate that most of the industries achieved positive TFP growth except a few; and thus within plant efficiency exists in Indian manufacturing sector. A further analysis of determinants of energy intensity using panel data model shows that productive plants in terms of TFP, are energy efficient. It is also observed that medium low-tech and high-tech industries on the basis of OECD classifications are energy efficient compared to the low-tech and the medium high-tech industries. The study also validates the "productivity dilemma hypothesis" for the sample firms indicating TFP and plant output are the major determinants of energy intensity.

Perfluorinated monolayer-coated TiO2 nanotube surfaces are repellent to a broad spectrum of liquids, and are not only of immediate interest in anti-fouling applications but also present a platform to explore wetting and imbibition phenomena in nanostructures.

Titanium nitride (TiN) is a ceramic with high electrical conductivity which in nanoparticle form, exhibits localized surface plasmon resonances (LSPRs) in the visible region of the solar spectrum. The ceramic nature of TiN coupled with its dielectric loss factor being comparable to that of gold, render it attractive for CMOS polarizers, refractory plasmonics, surface-enhanced Raman scattering and a whole host of sensing applications. We report core-shell TiO-TiN nanotube arrays exhibiting LSPR peaks in the range 775-830 nm achieved by a simple, solution-based, low cost, large area-compatible fabrication route that does not involve laser-writing or lithography. Self-organized, highly ordered TiO nanotube arrays were grown by electrochemical anodization of Ti thin films on fluorine-doped tin oxide-coated glass substrates and then conformally coated with a thin layer of TiN using atomic layer deposition. The effects of varying the TiN layer thickness and thermal annealing on the LSPR profiles were also investigated. Modeling the TiO-TiN core-shell nanotube structure using two different approaches, one employing effective medium approximations coupled with Fresnel coefficients, resulted in calculated optical spectra that closely matched the experimentally measured spectra. Modeling provided the insight that the observed near-infrared resonance was not collective in nature, and was mainly attributable to the longitudinal resonance of annular nanotube-like TiN particles redshifted due to the presence of the higher permittivity TiO matrix. The resulting TiO-TiN core-shell nanotube structures also function as visible light responsive photocatalysts, as evidenced by their photoelectrochemical water-splitting performance under light emitting diode illumination using 400, 430 and 500 nm photons.