scholarly journals Assembling Ultrafine SnO2 Nanoparticles on MIL-101(Cr) Octahedrons for Efficient Fuel Photocatalytic Denitrification

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7566
Author(s):  
Ruowen Liang ◽  
Shihui Wang ◽  
Yi Lu ◽  
Guiyang Yan ◽  
Zhoujun He ◽  
...  
Keyword(s):  
Sno2 Nanoparticles ◽  
Three Dimensional ◽  
High Dispersion ◽  
Environmental Restoration ◽  
Pure Sno2 ◽  
Facile Hydrothermal Method ◽  
Sunlight Irradiation ◽  
Adsorption Sites ◽  
The Rich ◽  
Nitrogen Containing Compounds

Effectively reducing the concentration of nitrogen-containing compounds (NCCs) remains a significant but challenging task in environmental restoration. In this work, a novel step-scheme (S-scheme) SnO2@MCr heterojunction was successfully fabricated via a facile hydrothermal method. At this heterojunction, MIL-101(Cr) octahedrons are decorated with highly dispersed SnO2 quantum dots (QDs, approximate size 3 nm). The QDs are evenly wrapped around the MIL-101(Cr), forming an intriguing zero-dimensional/three-dimensional (0D/3D) S-scheme heterostructure. Under simulated sunlight irradiation (280 nm < λ < 980 nm), SnO2@MCr demonstrated superior photoactivity toward the denitrification of pyridine, a typical NCC. The adsorption capacity and adsorption site of SnO2@MCr were also investigated. Tests using 20%SnO2@MCr exhibited much higher activity than that of pure SnO2 and MIL-101(Cr); the reduction ratio of Cr(VI) is rapidly increased to 95% after sunlight irradiation for 4 h. The improvement in the photocatalytic activity is attributed to (i) the high dispersion of SnO2 QDs, (ii) the binding of the rich adsorption sites with pyridine molecules, and (iii) the formation of the S-scheme heterojunction between SnO2 and MIL-101(Cr). Finally, the photocatalytic mechanism of pyridine was elucidated, and the possible intermediate products and degradation pathways were discussed.

scholarly journals A novel three-dimensional spherical CuBi2O4 consisting of nanocolumn arrays with persulfate and peroxymonosulfate activation functionalities for 1H-benzotriazole removal

Nanoscale ◽  
2015 ◽  
Vol 7 (17) ◽  
pp. 8149-8158 ◽  
Author(s):  
Wen-Da Oh ◽  
Shun-Kuang Lua ◽  
Zhili Dong ◽  
Teik-Thye Lim
Keyword(s):  
Hydrothermal Method ◽  
Three Dimensional ◽  
Facile Hydrothermal Method ◽  
Self Assembled

A novel CuBi2O4 consisting of self-assembled spherical nanocolumn arrays (CuB-H) was synthesized via a facile hydrothermal method.

scholarly journals The Three Dimensional Spiral of Sense: a New Paradigm Systemic Applied a Six Areas Disciplinares and Two Axis: Identity and Professionalization

2016 ◽  
Vol 4 (1) ◽  
pp. 40
Author(s):  
Miriam Aparicio
Keyword(s):  
Three Dimensional ◽  
Health Science ◽  
National Council ◽  
New Paradigm ◽  
Theoretical Frameworks ◽  
Systemic Theory ◽  
The Social ◽  
Different Populations ◽  
Generational Studies ◽  
The Rich

This article introduces a new systemic theory called “The Three Dimensional Spiral of Sense”, applied to Identity and Professionalization. The epistemological mainstays of the theory are stressed here, a theory supported by more than 30 years of empirical research at CONICET (National Council of Scientific Research, Argentina), with individuals belonging to different populations, some of them covering periods of over 20 years (intra-generational studies), and others covering three generations in-line (inter-generational studies). This article presents the most specific theoretical frameworks, and it formulates the six disciplinary areas in which the new analysis of the social data was carried out: Education, Health, Science, Media, International Relations and Interculturality. The first area – Education – is dealt with through different levels (secondary level, tertiary level, University and PhD training. Here, we only make reference to the studies carried out, returning to some epistemological issues in this theory. The methodology used was quantitative (statistical analysis, a semi-structured survey) but mainly qualitative (hierarchical evocations, interviews). The approach was macro-micro-meso-macro, micro, not quite common yet. It consists of a kind of sui generis systemism which recovers relationships (links, back and forth) between individuals and contexts, without overlooking neither the former nor the latter, thus, avoiding any type of reductionism. Individuals, organizations and frameworks interplay and feedback themselves. The results, particularly the qualitative ones, show the rich interactions underlying the continuance or innovation processes, which favor or hinder the individuals’ development and identity in times of abrupt change; at the same time, these results reveal the need for Professionalization in emerging countries.

A Non-Intrusive Experimental Technique for Constructing Poincaré Maps in 3D Chaotically Advected Flows

2001 ◽  
Author(s):  
Fotis Sotiropoulos ◽  
Igor Mezić ◽  
Donald R. Webster
Keyword(s):  
Light Intensity ◽  
Experimental Technique ◽  
Vortex Breakdown ◽  
Laser Sheet ◽  
Three Dimensional ◽  
Chaotic Advection ◽  
Time Averaging ◽  
Poincaré Maps ◽  
Poincare Maps ◽  
The Rich

Abstract We propose and develop the theoretical framework for a new experimental technique for constructing Poincaré maps in three-dimensional flows exhibiting chaotic advection. The technique is non-intrusive and, thus, simple to implement. Planar laser-induced fluorescence (LIF) is employed to collect a sufficiently long sequence of instantaneous light intensity fields on the plane of section of the Poincaré map (defined by the laser sheet). The chains of unmixed (regular) islands in the flow are visualized by time-averaging the instantaneous images and plotting iso-contours of the resulting mean light intensity field. A rigorous theoretical justification for this technique is derived using concepts from ergodic theory. We demonstrate the capabilities of the method by applying it to visualize the rich Lagrangian dynamics within steady vortex breakdown bubbles in a closed cylinder with a rotating bottom. The experimental results are shown to be in excellent agreement with numerical simulations.

scholarly journals Solar Light Harvesting N-Graphene Quantum Dots Decorated TiO2 for Enhanced Photocatalytic Activity

2018 ◽  
Vol 65 ◽  
pp. 05014
Author(s):  
Ping Feng Lim ◽  
Chen Hong Hak ◽  
Kah Hon Leong ◽  
Lan Ching Sim ◽  
Pichiah Saravanan
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Light Harvesting ◽  
Graphene Quantum Dots ◽  
Solar Light ◽  
Facile Hydrothermal Method ◽  
Sunlight Irradiation ◽  
Visible Light Range ◽  
Doped Graphene ◽  
Co Doped

N co-doped graphene quantum dots (N-GQDs) incorporated with nanocubic likes titanium dioxide (TiO2) are synthesized via facile hydrothermal method. The morphology features of the synthesized N-GQDs/TiO2 nanocomposites are seen to exhibited in cubic shape. The average lateral size of the synthesized nanocomposites is found to be ~5.1 nm. UV-Vis absorption spectra show vastly improvement in the visible light range when N-GQDs is introduced to TiO2. The photocatalytic activity clearly demonstrated its solar light harvesting capability of prepared nanocomposites by photodegrading 4-chlorophenol (4-CP) under sunlight irradiation.

scholarly journals Chromospheric Surface Structures on EI Eridani and HD 199178

1991 ◽  
Vol 130 ◽  
pp. 330-332
Author(s):  
James E. Neff
Keyword(s):  
Spatial Distribution ◽  
Effective Temperature ◽  
Three Dimensional ◽  
Stellar Atmospheres ◽  
Surface Structures ◽  
High Dispersion ◽  
The Sun ◽  
Late Type ◽  
Magnetic Topology ◽  
Radial Dimension

Several groups at this meeting are presenting maps of the spatial distribution of either brightness or effective temperature in the photospheres of rapidly-rotating, late-type stars. It is generally believed that structure seen in these maps traces the magnetic topology, in analogy with the Sun. We expect the structure of the outer atmospheres (i.e., chromosphere and corona) of these stars to be even more directly tied to the magnetic topology; the magnetic structure is three-dimensional. In order to probe the radial dimension of stellar atmospheres, we need to combine maps of the spatial distribution of emission from chromospheres and coronae with these detailed photospheric maps.Along with collaborators at Armagh, Catania, Boulder, Paris, Helsinki, and Stony Brook, I have been obtaining high-dispersion ultraviolet spectra of several rapidly-rotating, late-type stars using the IUE spacecraft. I discuss results for two stars, El Eridani and HD 199178, for which photospheric maps are presented elsewhere at this conference.

scholarly journals Streaming patterns in Faraday waves

2017 ◽  
Vol 819 ◽  
pp. 285-310 ◽  
Author(s):  
Nicolas Périnet ◽  
Pablo Gutiérrez ◽  
Héctor Urra ◽  
Nicolás Mujica ◽  
Leonardo Gordillo
Keyword(s):  
Three Dimensional ◽  
Navier Stokes ◽  
Faraday Waves ◽  
Three Dimensional Model ◽  
Inviscid Fluids ◽  
Streaming Velocity ◽  
The Rich ◽  
Set Up ◽  
Viscous Boundary ◽  
Streaming Flows

Wave patterns in the Faraday instability have been studied for decades. Besides the rich wave dynamics observed at the interface, Faraday waves hide elusive flow patterns in the bulk – streaming patterns – which have not been studied experimentally. The streaming patterns are responsible for a net circulation in the flow, which is reminiscent of the circulation in convection cells. In this article, we analyse these streaming flows by conducting experiments in a Faraday-wave set-up using particle image velocimetry. To visualise the flows, we perform stroboscopic measurements to both generate trajectory maps and probe the streaming velocity field. We identify three types of patterns and experimentally show that identical Faraday waves can mask streaming patterns that are qualitatively very different. Next, we consider a three-dimensional model for streaming flows in quasi-inviscid fluids, whose key is the complex coupling occurring at all of the viscous boundary layers. This coupling yields modified boundary conditions in a three-dimensional Navier–Stokes formulation of the streaming flow. Numerical simulations based on this framework show reasonably good agreement, both qualitative and quantitative, with the velocity fields of our experiments. The model highlights the relevance of three-dimensional effects in the streaming patterns. Our simulations also reveal that the variety of streaming patterns is deeply linked to the boundary condition at the top interface, which may be strongly affected by the presence of contaminants.

Preparation and Optical Properties of TiO2 Film with a Nest-Like Structure by Three Times of Circulating Hydrothermal Method

NANO ◽  
2016 ◽  
Vol 11 (06) ◽  
pp. 1650066 ◽  
Author(s):  
Quangui He ◽  
Jia Zhuang ◽  
Qiuxiang Wen ◽  
Yang Deng ◽  
Jun Yu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Hydrothermal Method ◽  
Three Dimensional ◽  
Dye Adsorption ◽  
Photoelectric Conversion Efficiency ◽  
Photoelectric Conversion ◽  
Facile Hydrothermal Method ◽  
Conductive Glass ◽  
Photoelectric Properties ◽  
Adsorption Amount

An anatase TiO2 photoanode with a novel three-dimensional nest-like structure was prepared directly on a transparent conductive glass substrate through hydrothermal cycles by three times. First, an unidirectional banded structure film was prepared by a facile hydrothermal method. And then, with the time of hydrothermal cycle increased, part of nanobelts were ruptured into a lot of small polyhedrons, but they still maintained a trend of the previous connection, and some fine nanobelts were interweaved in small polyhedrons. Finally, we successfully prepared a film with a novel 3D nest-like structure, and it had all the characteristics of the hierarchitectures. It had better photoelectric properties than the film with fewer times of hydrothermal cycle. Its photoelectric conversion efficiency reached 3.81%, which is due to a large dye adsorption amount, rapid electronic transmission, and superior light scattering and more electrons transmission paths.

Preparation and Characterization of Cerium-Doped Tin Oxide Gas Sensors

2011 ◽  
Vol 306-307 ◽  
pp. 1450-1455 ◽  
Author(s):  
Hong Yan Xu ◽  
Xing Qiao Chen ◽  
Ling Zhan Fang ◽  
Bing Qiang Cao
Keyword(s):  
Thick Film ◽  
Gas Sensors ◽  
Tin Oxide ◽  
Sno2 Nanoparticles ◽  
Raw Material ◽  
Pure Sno2 ◽  
Acetone Vapor ◽  
Intrinsic Resistance ◽  
Microwave Hydrothermal

In this paper, the precursors were synthesized by microwave hydrothermal method using SnCl4•5H2O and Ce(NO3)3·6H2O as raw material, CO(NH2)2 as precipitants, respectively. Pure SnO2 nanoparticles and cerium-doped SnO2 nanoparticles were obtained. Furthermore, five kinds of SnO2 thick film gas sensors were fabricated from the above SnO2 nanoparticles (the sensors denoted as sensor SC0, SC2, SC3, SC4 and SC6, respectively). The experiment results showed that, compared with pure SnO2 thick film gas sensor, the intrinsic resistance of cerium-doped SnO2 thick film gas sensors decreased, and their sensor responses to acetone vapor increased, which are discussed in relation to the SEM micrographs of thick film sensors.

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