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Results for “Nanorice”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Influence of nitrogen content levels on structural properties and photocatalytic activities of nanorice-like N-doped TiO2 with various calcination temperatures

Highlights: • Hydrothermal method enhances the integration of N species into TiO{sub 2}. • TiO{sub 2} doping with nitrogen prevents the phase transformation from anatase to rutile. • The N-doped TiO{sub 2} exhibits nanorice-like morphology. • Nitrogen atom incorporates into the lattice of TiO{sub 2} with interstitial site (TiON). • Nitrogen doping content in TiO{sub 2} accelerates the kinetic rate of photocatalytic reaction. - Abstract: The purposes of this research were to study the effect of nitrogen content levels on structural properties and photocatalytic activities of catalysts with various calcination temperatures and to test the photocatalytic degradation of paraquat under UV and visible light. The results showed that the effect of calcination temperature was significant on physical properties and amount of nitrogen element, but insignificant on phase structure and oxidation state of titanium (Ti) atom. The N-doped TiO2 samples demonstrated only anatase phase because nitrogen dopant in TiO2 restrained the phase transformation from anatase to rutile and displayed nanorice-like morphology. The bandgap energy was about 3.07–3.18 eV. The nitrogen content was only observed at 100, 300 and 400 °C. The nitrogen (N) atom can be incorporated in TiO2 structural lattice with interstitial site. The specific surface area and nitrogen content level showed the important roles for the photodegradation of paraquat under UV and visible light irradiation.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS2010

Nanorice Particles: Hybrid Plasmonic Nanostructures

A new hybrid nanoparticle, i.e., a nanorice particle, which combines the intense local fields of nanorods with the highly tunable plasmon resonances of nanoshells, is described herein. This geometry possesses far greater structural tunability than previous nanoparticle geometries, along with much larger local field enhancements and far greater sensitivity as a surface plasmon resonance (SPR) nanosensor than presently known dielectric-conductive material nanostructures. In an embodiment, a nanoparticle comprises a prolate spheroid-shaped core having a first aspect ratio. The nanoparticle also comprises at least one conductive shell surrounding said prolate spheroid-shaped core. The nanoparticle has a surface plasmon resonance sensitivity of at least 600 nm RIU(sup.-1). Methods of making the disclosed nanorice particles are also described herein.

Wang, Hui↗
DOE OSTI2022

High pressure induced atomic and mesoscale phase behaviors of one-dimensional TiO 2 anatase nanocrystals

Here, we report the high pressure phase and morphology behavior of ordered anatase titanium dioxide (TiO 2 ) nanocrystal arrays. One-dimensional TiO 2 nanorods and nanorices were synthesized and self-assembled into ordered mesostructures. Their phase and morphological transitions at both atomic scale and mesoscale under pressure were studied using in situ synchrotron wide- and small-angle x-ray scattering (WAXS and SAXS) techniques. At the atomic scale, synchrotron WAXS reveals a pressure-induced irreversible amorphization up to 35 GPa in both samples but with different onset pressures. On the mesoscale, no clear phase transformations were observed up to 20 GPa by synchrotron SAXS. Intriguingly, sintering of TiO 2 nanorods at mesoscale into nano-squares or nano-rectangles, as well as nanorices into nanowires, were observed for the first time by transmission electron microscopy. Such pressure-induced nanoparticle phase-amorphization and morphological changes provide valuable insights for design and engineering structurally stable nanomaterials.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Component Particle Structure in Heterogeneous Disordered Ensembles Extracted from High-Throughput Fluctuation X-Ray Scattering

The ring angular correlation function is a characteristic feature determined by the particle structure. Averaging over a large number of ring angular correlation functions calculated from x-ray diffraction patterns will cancel out the cross correlations between different particles and converge to the autocorrelation functions of single particles. Applied on heterogeneous disordered ensembles, the retrieved function is a linear combination of a single-particle autocorrelation function multiplied by the molar ratios in a heterogeneous system. Using this relation, the ring angular correlation functions of the individual component particles in the heterogeneous system can be retrieved through the high throughput fluctuation x-ray scattering technique. This method is demonstrated with a simulated heterogeneous system composed of nanorods, nanoprism, and nanorice.

Fluctuation X-ray Scattering, high throughput, Het↗