Nanotubes to Order To exploit carbon nanotubes fully in electronic applications, one needs be able separate or synthesize either all semiconducting metallic tubes. However, unbiased synthesis conditions produce a mixture containing two-thirds tubes and one-third Harutyunyan et al. (p. 116 ) show that altering the carrier gas temperature, combination with oxidative reductive species during process modifies catalyst particles synthesis, which leads selective growth of single-walled nanotubes....

The water-gas shift (WGS) reaction rate per total mole of Au under 7% CO, 8.5% CO(2), 22% H(2)O, and 37% H(2) at 1 atm for Au/Al(2)O(3) catalysts 180 °C Au/TiO(2) 120 varies with the number average particle size (d) as d(-2.2±0.2) d(-2.7±0.1), respectively. use nonporous crystalline, model Al(2)O(3) TiO(2) supports allowed imaging active catalyst enabled a precise determination distribution shape using transmission electron microscopy (TEM). Further, apparent orders stretching frequency CO...

The Ostwald ripening behavior of Fe catalyst films deposited on thin alumina supporting layers is demonstrated as a function thermal annealing in H2 and H2/H2O. addition H2O super growth single-walled carbon nanotube carpets observed to inhibit due the ability oxygen hydroxyl species reduce diffusion rates atoms. This work shows impact typical carpet environments film evolution role may play termination growth.

We use transmission electron microscopy (TEM) to investigate the evolution of surface structure LixNi0.8Co0.15Al0.05O2 cathode materials (NCA) as a function extent first charge at room temperature using combination high-resolution (HREM) imaging, selected area diffraction (SAED), and energy loss spectroscopy (EELS). It was found that changes from layered (space group R3̅m) disordered spinel (Fd3̅m), eventually rock-salt (Fm3̅m), these are more substantial increases. EELS indicates crystal...

Abstract Developing methods to assemble nanomaterials into macroscopic scaffolds is of critical significance at the current stage nanotechnology. However, complications fabrication impede widespread usages newly developed materials even with superior properties in many cases. Here, we demonstrate feasibility a highly-efficient and potentially-continuous fiber-spinning method produce high-performance carbon nanotube (CNT) fiber (CNTF). The processing time <1 min from synthesis CNTs highly...

Abstract Thermoelectric technology has potential for converting waste heat into electricity. Although traditional thermoelectric materials exhibit extremely high performances, their scarcity and toxicity limit applications. Zinc oxide (ZnO) emerges as a promising alternative owing to its thermal stability relatively Seebeck coefficient, while also being earth-abundant nontoxic. However, conductivity (>40 W m −1 K ) remains challenge. In this study, we use multi-step strategy achieve...

We have studied the lifetime, activity, and evolution of Fe catalysts supported on different types alumina: (a) sputter deposited alumina films (sputtered/Fe), (b) electron-beam (e-beam/Fe), (c) annealed e-beam (annealed e-beam/Fe), (d) by atomic layer deposition (ALD/Fe), (e) c-cut sapphire (sapphire/Fe). show that catalytic behavior, Ostwald ripening, subsurface diffusion rates catalyst during water-assisted growth or “supergrowth” single-walled carbon nanotube (SWNT) carpets are strongly...

A mechanism by which catalyst deactivation occurs during vertically aligned single-walled carbon nanotube (SWNT) growth is demonstrated. We have used both quantitative measurements of rates and ex situ in transmission electron microscopy observations to show that termination (CNT) array can be intrinsically linked evolution the morphology. Specifically, we find a combination Ostwald ripening subsequent subsurface diffusion leads loss Fe catalyst, through direct observations, correlate this...

Au/TiO(2) catalysts used in the water-gas shift (WGS) reaction at 120 °C, 7% CO, 22% H(2)O, 9% CO(2), and 37% H(2) had rates up to 0.1 moles of CO converted per mole Au second. However, rate depends strongly on particle size. The use a nonporous, model support allowed for imaging active catalyst precise determination gold size distribution using transmission electron microscopy (TEM) because all is exposed surface. A physical show that corner atoms with fewer than seven neighboring are...

Abstract Hexagonal molybdenum diselenide (MoSe 2 ) multilayers were grown by chemical vapor deposition (CVD). A relatively high pressure (>760 Torr) was used during the CVD growth to achieve creating multiple nuclei based on two-dimensional crystal model. Our CVD-grown multilayer MoSe thin-film transistors (TFTs) show p-type-dominant ambipolar behaviors, which are attributed formation of Se vacancies generated at decomposition temperature (650 °C) after for 10 min. TFT with a reasonably...

Platinum atomic layer deposition (ALD) using MeCpPtMe3 was employed to prepare high loadings of uniform-sized, 1−2 nm Pt nanoparticles on surface area Al2O3, TiO2, and SrTiO3 supports. X-ray absorption fine structure utilized monitor the changes in species during each step synthesis. The temperature, precursor exposure time, treatment gas, number ALD cycles were found affect particle size density. Lower-temperature adsorption yielded smaller particles due reduced thermal decomposition. A 300...

In this work, we use in situ transmission electron microscopy (TEM) to investigate the thermal decomposition that occurs at surface of charged LixNiyMnzCo1–y–zO2 (NMC) cathode materials different composition (with y, z = 0.8, 0.1, and 0.6, 0.2, 0.4,and 0.3), after they have been their practical upper limit voltage (4.3 V). By heating these inside TEM, are able directly characterize near changes both electronic structure (using energy loss spectroscopy) crystal morphology diffraction...

Large-area and highly crystalline CVD-grown multilayer MoSe2 films exhibit a well-defined crystal structure (2H phase) large grains reaching several hundred micrometers. Multilayer transistors high mobility up to 121 cm2 V−1 s−1 excellent mechanical stability. These results suggest that materials will be indispensable for various future applications such as high-resolution displays human-centric soft electronics. As service our authors readers, this journal provides supporting information...

A one-pot conversion of monosaccharides (fructose and glucose) into high-yield 2,5-dimethylfuran (2,5-DMF) is demonstrated over a multifunctional catalyst obtained by loading Pd on UiO-66@ sulfonated GO (Pd/UiO-66@SGO).

In this work, we take advantage of in situ transmission electron microscopy (TEM) to investigate thermally induced decomposition the surface Li(x)Ni(0.8)Co(0.15)Al(0.05)O2 (NCA) cathode materials that have been subjected different states charge (SOC). While uncharged NCA is stable up 400 °C, significant changes occur charged with increasing temperature. These include development porosity and oxygen K-edge energy loss spectra, pre-edge peaks shifting higher losses. are closely related O2 gas...

Recently, fire accidents in buildings have become bigger around the world, and it has necessary to build an efficient building disaster management system suitable for fires a Smart City. As increase number of casualties property damage, is take appropriate action accordingly. There been increasing effort develop such systems worldwide by applying information communication technology (ICT), many studies conducted practice. In this paper, augmented reality (AR)-based Building Town Disaster...

An efficient bimetallic ZnO/Co@N-CNT catalyst was designed for selective hydrogenation and hydrodeoxygenation of lignin its derived components in water.

One-dimensional nanostructures exhibit quantum confinement which leads to unique electronic properties, making them attractive as the active elements for nanoscale devices. Boron nitride nanotubes are of particular interest since, unlike carbon nanotubes, all chiralities semiconducting. Here, we report a synthesis based on use low pressures molecular precursor borazine in conjunction with floating nickelocene catalyst that resulted formation double-walled boron nanotubes. As has been shown...

In this work, we investigate the structural modifications occurring at bulk, subsurface, and surface scales of LixNiyMnzCo1–y–zO2 (NMC; y, z = 0.8, 0.1 0.4, 0.3, respectively) cathode materials during initial charge/discharge. Various analytical tools, such as X-ray diffraction, selected-area electron energy-loss spectroscopy, high-resolution microscopy, are used to examine properties NMC three different scales. Cutoff voltages 4.3 4.8 V applied electrochemical tests normal extreme...