scholarly journals Bi6Te2-xRxO13 (R=Ti, Si, Ce) Systems: A Investigation for Fuel Cell Applications

2021 ◽  
Vol 19 ◽  
pp. 246-250
Author(s):  
K.D. Ferreira ◽  
◽  
G. Gasparatto ◽  
G.P. Viajante ◽  
J.F. Carvalho ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid State ◽  
Room Temperature ◽  
Materials Science ◽  
Renewable Energy Sources ◽  
Functional Materials ◽  
Cubic Phase ◽  
Ionic Conductors ◽  
Materials Synthesis ◽  
Promising Alternative

In recent years, the increase of economic and environmental problems related to energy generation has increased researches at renewable energy sources. Among others, the fuel cells excel as promising alternative technology of electricity generation and materials science is an ally in the search for better and more efficient materials for this application. In particular, solid-state ionic conductors represent functional materials with promising advantages for fuel cells, as is the case of Bi2O3-based oxygen ion conductors, however, they need to have its cubic phase stabilized at room temperature. This paper presents a study of the Bi6Te2-xRxO13 (R = Ti, Si and Ce) systems for such an application. Solid state reaction was used to materials synthesis. The 3Bi2O3:2TeO2 system present two phases, an orthorhombic one (Bi6Te2O15) stable at room temperature and another high temperature cubic (Bi6Te2O13). Experiments of substitution of Te ions by Ti, Si and Ce ions using the Bi6Te2- xRxO13 matrix were done intending to stabilize the cubic phase at room temperature and the results are presented as well as discussed here.

scholarly journals Synthesis of Cubic Phase-Co Microspheres by Mechanical Solid-State Reaction-Thermal Decomposition and Research on Its Growth Kinetics

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ying Deng ◽  
Yanhua Zhang ◽  
Lingling Peng ◽  
Xiaolong Jing ◽  
Hui Chen
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Grain Growth ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Energy Content ◽  
Industrial Applications ◽  
Cubic Phase ◽  
Oxalate Precursor ◽  
Cobalt Oxalate

Cubic phase cobalt (Co), which can be used as a key component for composite materials given its excellent ductility and internal structure, is not easy to obtain at room temperature. In this study, oxalic acid and cobalt nitrate are used as raw materials to synthesize the cobalt oxalate precursor, which has a stable structure with a five-membered chelate ring. Cobalt oxalate microspheres, having a high internal energy content, were prepared by using mechanical solid-state reaction in the presence of a surfactant, which can produce spherical micelles. The thermal decomposition of the precursor was carried out by maintaining it in a nitrogen atmosphere at 450°C for 3 h. At the end of the procedure, 100 nm cubic phase-Co microspheres, stable at room temperature, were obtained. Isothermal and nonisothermal kinetic mechanisms of cobalt grain growth were investigated. The cubic-Co grain growth activation energy, Q, was calculated in this study to be 71.47 kJ/mol. The required reaction temperature was low, making the production process simple and suitable for industrial applications.

scholarly journals Continuous- versus Segmented-Flow Microfluidic Synthesis in Materials Science

Crystals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 12 ◽  
Author(s):  
Mathieu Gonidec ◽  
Josep Puigmartí-Luis
Keyword(s):  
Continuous Flow ◽  
Materials Science ◽  
Low Cost ◽  
Parallel Evolution ◽  
Reaction Diffusion ◽  
Functional Materials ◽  
Microfluidic Devices ◽  
Research Field ◽  
Segmented Flow ◽  
Materials Synthesis

Materials science is a fast-evolving area that aims to uncover functional materials with ever more sophisticated properties and functions. For this to happen, new methodologies for materials synthesis, optimization, and preparation are desired. In this context, microfluidic technologies have emerged as a key enabling tool for a low-cost and fast prototyping of materials. Their ability to screen multiple reaction conditions rapidly with a small amount of reagent, together with their unique physico-chemical characteristics, have made microfluidic devices a cornerstone technology in this research field. Among the different microfluidic approaches to materials synthesis, the main contenders can be classified in two categories: continuous-flow and segmented-flow microfluidic devices. These two families of devices present very distinct characteristics, but they are often pooled together in general discussions about the field with seemingly little awareness of the major divide between them. In this perspective, we outline the parallel evolution of those two sub-fields by highlighting the key differences between both approaches, via a discussion of their main achievements. We show how continuous-flow microfluidic approaches, mimicking nature, provide very finely-tuned chemical gradients that yield highly-controlled reaction–diffusion (RD) areas, while segmented-flow microfluidic systems provide, on the contrary, very fast homogenization methods, and therefore well-defined super-saturation regimes inside arrays of micro-droplets that can be manipulated and controlled at the milliseconds scale. Those two classes of microfluidic reactors thus provide unique and complementary advantages over classical batch synthesis, with a drive towards the rational synthesis of out-of-equilibrium states for the former, and the preparation of high-quality and complex nanoparticles with narrow size distributions for the latter.

scholarly journals A sodium-ion sulfide solid electrolyte with unprecedented conductivity at room temperature

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
A. Hayashi ◽  
N. Masuzawa ◽  
S. Yubuchi ◽  
F. Tsuji ◽  
C. Hotehama ◽  
...  
Keyword(s):  
Solid State ◽  
Room Temperature ◽  
Sodium Ion ◽  
Partial Substitution ◽  
Cubic Phase ◽  
Ongoing Research ◽  
Temperature Conductivity ◽  
Humid Atmosphere ◽  
Room Temperature Conductivity ◽  
Ion Conductors

AbstractSolid electrolytes are key materials to enable solid-state rechargeable batteries, a promising technology that could address the safety and energy density issues. Here, we report a sulfide sodium-ion conductor, Na2.88Sb0.88W0.12S4, with conductivity superior to that of the benchmark electrolyte, Li10GeP2S12. Partial substitution of antimony in Na3SbS4 with tungsten introduces sodium vacancies and tetragonal to cubic phase transition, giving rise to the highest room-temperature conductivity of 32 mS cm−1 for a sintered body, Na2.88Sb0.88W0.12S4. Moreover, this sulfide possesses additional advantages including stability against humid atmosphere and densification at much lower sintering temperatures than those (>1000 °C) of typical oxide sodium-ion conductors. The discovery of the fast sodium-ion conductors boosts the ongoing research for solid-state rechargeable battery technology with high safety, cost-effectiveness, large energy and power densities.

scholarly journals A graph-based network for predicting chemical reaction pathways in solid-state materials synthesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew J. McDermott ◽  
Shyam S. Dwaraknath ◽  
Kristin A. Persson
Keyword(s):  
Solid State ◽  
Chemical Reaction ◽  
Reaction Pathway ◽  
Reaction Network ◽  
Functional Materials ◽  
Reaction Pathways ◽  
Materials Synthesis ◽  
Pathway Prediction ◽  
Solid State Materials ◽  
Cost Paths

AbstractAccelerated inorganic synthesis remains a significant challenge in the search for novel, functional materials. Many of the principles which enable “synthesis by design” in synthetic organic chemistry do not exist in solid-state chemistry, despite the availability of extensive computed/experimental thermochemistry data. In this work, we present a chemical reaction network model for solid-state synthesis constructed from available thermochemistry data and devise a computationally tractable approach for suggesting likely reaction pathways via the application of pathfinding algorithms and linear combination of lowest-cost paths in the network. We demonstrate initial success of the network in predicting complex reaction pathways comparable to those reported in the literature for YMnO3, Y2Mn2O7, Fe2SiS4, and YBa2Cu3O6.5. The reaction network presents opportunities for enabling reaction pathway prediction, rapid iteration between experimental/theoretical results, and ultimately, control of the synthesis of solid-state materials.

Fungus-mediated Biological Approaches Towards 'Green' Synthesis of Oxide Nanomaterials

2011 ◽  
Vol 64 (3) ◽  
pp. 279 ◽  
Author(s):  
Vipul Bansal ◽  
Rajesh Ramanathan ◽  
Suresh K. Bhargava
Keyword(s):  
Large Scale ◽  
Materials Science ◽  
Functional Materials ◽  
Environmentally Benign ◽  
Current Status ◽  
Biological Synthesis ◽  
Materials Synthesis ◽  
Nanomaterials Synthesis ◽  
Critical Overview ◽  
Promising Avenue

A promising avenue of research in materials science is to follow the strategies used by nature to fabricate ornate hierarchical materials. For many ages, organisms have been engaged in on-the-job testing to craft structural and functional materials and have evolved extensively to possibly create the best-known materials. Some of the strategies used by nature may well have practical implications in the world of nanomaterials. Therefore, the efforts to exploit nature’s ingenious work in designing strategies for nanomaterials synthesis has led to biological routes for materials synthesis. This review outlines the biological synthesis of a range of oxide nanomaterials that has hitherto been achieved using fungal biosynthesis routes. A critical overview of the current status and future scope of this field that could potentially lead to the microorganism-mediated commercial, large-scale, environmentally benign, and economically-viable ‘green’ syntheses of oxide nanomaterials is also discussed.

Photochromism of Neutral Spiropyran in the Crystalline State at Room Temperature

2021 ◽  
Author(s):  
Zhen Wu ◽  
Qian Wang ◽  
Pengyu Li ◽  
Bing Fang ◽  
Meizhen Yin
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Crystalline State ◽  
Room Temperature ◽  
Functional Materials ◽  
Photochromic Material ◽  
Tunable Optical Properties ◽  
Photochromic Materials

Solid-state photochromic materials are very attractive due to their promising future in advanced functional materials with reversible and tunable optical properties. However, the development of photochromic material in the solid...

Structural and Morphologies of (1-x)BaTiO3-xBaFe0.5Nb0.5O3 Solid Solution

2008 ◽  
Vol 55-57 ◽  
pp. 137-140 ◽  
Author(s):  
Sukum Eitssayeam
Keyword(s):  
Solid Solution ◽  
Structural Change ◽  
Solid State ◽  
Room Temperature ◽  
Xrd Analysis ◽  
Dielectric Measurement ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Temperature Changes ◽  
X Ray

The structural and physical properties of(1−x)BaTiO3 –xBaFe0.5Nb0.5O3 ceramics system were investigated as a function of the BaFe0.5Nb0.5O3 content by X-ray diffraction (XRD) and dielectric measurement technique. Studies were performed on the samples prepared by solid state reaction for x = 0, 0.2, 0.4 and 0.6. The XRD analysis demonstrated that with increasing BFN content in (1−x)BT–xBFN, the structural change occurred from the tetragonal to the cubic phase at room temperature. Changes in the morphology were then related to these structural depending on the BFN content.

Phase relations in the Ba–Sr–Co–Fe–O system at 1273 K in air

2009 ◽  
Vol 42 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Zhèn Yáng ◽  
Ashley S. Harvey ◽  
Anna Infortuna ◽  
Ludwig J. Gauckler
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Solid State Reaction Method ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray

Selected compositions of the Ba–Sr–Co–Fe–O system were synthesized from powders by the solid-state reaction method. Samples were equilibrated at 1273 K for 36 000 s in air. The resulting powders were characterized by X-ray diffraction (XRD) at room temperature and by high-temperaturein situXRD. The phases present in the BaxSr1−xCoyFe1−yO3−δsystem are outlined for 1273 K in air. For most of the quaternary compositions, the cubic perovskite is formed, except for the compositions withx= 1 (excludingy= 0.4),y= 1 andx,y= 0.8, where the phases mainly show hexagonal distortions, andx, y= 0, for which a predominant cubic phase is mixed with other phases.

scholarly journals Thin film oxide-ion conducting electrolyte for near room temperature applications

2019 ◽  
Vol 7 (45) ◽  
pp. 25772-25778 ◽  
Author(s):  
Iñigo Garbayo ◽  
Francesco Chiabrera ◽  
Nerea Alayo ◽  
José Santiso ◽  
Alex Morata ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solid State ◽  
Room Temperature ◽  
Bismuth Vanadate ◽  
Ionic Conductors ◽  
Electrochemical Devices ◽  
Ion Conducting ◽  
Oxide Ion ◽  
Temperature Applications

Stabilized bismuth vanadate thin films are presented here as superior oxide ionic conductors, for application in solid state electrochemical devices operating near room temperature.

HYDROGEN BASED ENERGY STORAGE: STATUS AND RECENT DEVELOPMENTS

2021 ◽  
Author(s):  
Volodymyr Yartys ◽  
◽  
Yuriy Solonin ◽  
Ihor Zavaliy ◽  
◽  
...  
Keyword(s):  
Power Systems ◽  
Materials Science ◽  
Renewable Energy Sources ◽  
Functional Materials ◽  
Efficient Production ◽  
National Academy Of Sciences ◽  
Production Of Hydrogen ◽  
Scientific Principles ◽  
Technology Coordinator ◽  
Priority Program

The book presents the recent achievements in the use of renewable energy sources, chemical processes, biomaterials for the efficient production of hydrogen, its storage and use as a fuel in the FC-based power systems. Novel results were obtained within two research programs, namely, the NATO Science for Peace G5233 project “Portable Energy Supply” (2017-21) and the priority program of the NAS of Ukraine "Development of scientific principles of the production, storage and use of hydrogen in autonomous energy systems" (2019-21). The priority program was implemented by the leading institutes of the National Academy of Sciences of Ukraine and contained three focus areas: efficient materials and technologies for the production, storage and use of hydrogen. This includes the development of new functional materials for the fuel cells and the application of the latter in autonomous power supply systems. 4-years NATO's project was implemented by a consortium led by the Institute for Energy Technology (Coordinator; NATO country - Norway) together with the institutes from the NATO partner country – Ukraine – belonging to the NAS of Ukraine: Physico-Mechanical Institute, Institute for Problems of Materials Science and Institute of General and Inorganic Chemistry. The work included the studies of H2 generation by the hydrolysis of MgH2, Al and NaBH4, analysis of the mechanisms of these processes and selection of the most efficient catalyzers. The project successfully developed a system integrating hydrolysis process and a PEM fuel cell.

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