scholarly journals Photo-Chlorine Production with Hydrothermally Grown and Vacuum-Annealed Nanocrystalline Rutile

2020 ◽  
Vol 12 (1) ◽  
pp. 65-77
Author(s):  
Thom R. Harris-Lee ◽  
Yan Zhang ◽  
Christopher R. Bowen ◽  
Philip J. Fletcher ◽  
Yuanzhu Zhao ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Energy Surface ◽  
Vacuum Annealing ◽  
Surface States ◽  
Annealing Treatment ◽  
High Energy ◽  
Proof Of Concept ◽  
Surface Species ◽  
Aqueous Environments ◽  
Bulk Semiconductor

AbstractPhoto-generated high-energy surface states can help to produce chlorine in aqueous environments. Here, aligned rutile (TiO2) nanocrystal arrays are grown onto fluorine-doped tin oxide (FTO) substrates and activated either by hydrothermal Sr/Ba surface doping and/or by vacuum-annealing. With vacuum-annealing, highly photoactive films are obtained with photocurrents of typically 8 mA cm−2 at 1.0 V vs. SCE in 1 M KCl (LED illumination with λ = 385 nm and approx. 100 mW cm−2). Photoelectrochemical chlorine production is demonstrated at proof-of-concept scale in 4 M NaCl and suggested to be linked mainly to the production of Ti(III) surface species by vacuum-annealing, as detected by post-catalysis XPS, rather than to Sr/Ba doping at the rutile surface. The vacuum-annealing treatment is proposed to beneficially affect (i) bulk semiconductor TiO2 nanocrystal properties and electron harvesting, (ii) surface TiO2 reactivity towards chloride adsorption and oxidation, and (iii) FTO substrate performance.

scholarly journals Influence of V and Heat Treatment on Characteristics of WMoNbTaV Refractory High-Entropy Alloy Coatings by Mechanical Alloying

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 265
Author(s):  
Chun-Liang Chen ◽  
Sutrisna
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Annealing Treatment ◽  
High Energy ◽  
304 Stainless Steel ◽  
Homogeneous Distribution ◽  
High Entropy Alloy ◽  
Solid Solution Phase ◽  
High Entropy ◽  
Steel Substrates

Refractory high-entropy alloy (RHEA) is one of the most promising materials for use in high-temperature structural materials. In this study, the WMoNbTaV coatings on 304 stainless steel substrates has been prepared by mechanical alloying (MA). Effects of V addition and subsequent heat treatment on properties of the WMoNbTaV coatings were investigated. The results show that the RHEA coatings with nanocrystalline body-centered cubic (BCC) solid-solution phase were generated by the mechanical alloying process. The presence of the V element promotes a uniform microstructure and homogeneous distribution of composition in the RHEA coatings due to improving alloying efficiency, resulting in an increase of hardness. After the annealing treatment of the RHEA coatings, microstructure homogeneity was further enhanced; however, the high affinity of Ta for oxygen causes the formation of Ta-rich oxides. Annealing also removes strain hardening generated by high-energy ball milling and thus decreases the hardness of the RHEA coating and alters microstructure evolution and mechanical properties.

A high-voltage aqueous lithium ion capacitor with high energy density from an alkaline–neutral electrolyte

2019 ◽  
Vol 7 (8) ◽  
pp. 4110-4118 ◽  
Author(s):  
Chunyang Li ◽  
Wenzhuo Wu ◽  
Shuaishuai Zhang ◽  
Liang He ◽  
Yusong Zhu ◽  
...  
Keyword(s):  
Energy Density ◽  
High Voltage ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Carbon Anode ◽  
Biomass Carbon ◽  
Proof Of Concept ◽  
Lithium Ion Capacitor ◽  
Neutral Electrolyte

A proof-of-concept lithium ion capacitor comprising LiMn2O4 nanorods as the cathode, a nitrogen-rich biomass carbon anode and a stable alkaline–neutral electrolyte was designed and fabricated.

scholarly journals Creation and Evaluation of Atomically Ordered Side- and Facet-Surface Structures of Three-Dimensional Silicon Nano-Architectures

2020 ◽  
Author(s):  
Azusa N. Hattori ◽  
Ken Hattori
Keyword(s):  
Electron Diffraction ◽  
Surface Science ◽  
Three Dimensional ◽  
Annealing Treatment ◽  
High Energy ◽  
Energy Electron ◽  
Atomic Scale ◽  
Methods Of Evaluation ◽  
Facet Surface ◽  
Microscopy Techniques

The realization of three-dimensional (3D)-architected nanostructures, that is, the transformation from novel two-dimensional (2D) film-based devices to 3D complex nanodevices, is of crucial importance with the progress of scaling down devices to nanometer order. However, little attention has been devoted to controlling the atomic ordering and structures of side-surfaces on 3D structures, while techniques for controlling and investigating 2D surfaces, namely, surface science, have been established only for planar 2D surfaces. We have established an original methodology that enables atomic orderings and arrangements of surfaces with arbitrary directions to be observed on 3D figured structures by developing diffraction and microscopy techniques. An original technique, namely, directly and quantitatively viewing the side- and facet-surfaces at the atomic scale by reflection high-energy electron diffraction (RHEED) and low-energy electron diffraction (LEED), can be used to determine process parameters in etching. This chapter introduces methods of evaluation by RHEED and LEED based on a reciprocal space map and methods of creating various atomically flat 111 and {100} side-surfaces of 3D Si nano-architectures and tilted 111 facet-surfaces fabricated by lithography dry and wet etching processes, followed by annealing treatment in vacuum.

Structural and Magnetocaloric Properties of Ball Milled LaFe13−xSix(H,C)y

MRS Advances ◽  
2017 ◽  
Vol 2 (56) ◽  
pp. 3447-3452
Author(s):  
L. Bessais ◽  
M. Phejar ◽  
V. Paul-Boncour
Keyword(s):  
Curie Temperature ◽  
Magnetic Moments ◽  
Synthesis Method ◽  
Annealing Treatment ◽  
Interstitial Site ◽  
High Energy ◽  
Magnetocaloric Properties ◽  
Magnetovolume Effect ◽  
Short Annealing ◽  
Giant Magnetocaloric Effect

ABSTRACTLaFe13−xSix compounds display a giant magnetocaloric effect near 200 K. The insertion of light elements (H, C) is used to improve the Curie temperature near ambient temperature for magnetic refrigeration applications. We have developed a synthesis method with a short annealing treatment compared to classical melting techniques. The parent intermetallic alloys were synthesized by high energy ball milling. The insertion of H atoms was carried out using a Sievert apparatus and the carbon atom was inserted by solid/solid reaction. Moreover, structural and magnetic results were carried out by neutron diffraction and Mössbauer spectrometry for H content (y = 0.7,1.5) and C content (y = 0.7). The cell parameter and the Fe magnetic moments versus temperature are determined. The misunderstanding on interstitial site is clarified. The magnetovolume effect on the Curie temperature is explained by combination of the structural and magnetic properties. The advantages and drawbacks of each type of element insertion are discussed.

The Development of the High Energy Surface Discharge Spark Igniter

1984 ◽  
Author(s):  
G. N. Burland ◽  
K. A. Goreham ◽  
R. J. Taunt
Keyword(s):  
Energy Surface ◽  
High Energy ◽  
Point Of View ◽  
Surface Discharge ◽  
Operational Life

The High Energy Igniter is discussed from the point of view of its mechanism of operation and of factors which determine its operational life. Features of the engine environment and operation are considered in their effect on igniter life. The problems associated with continuous ignition and the overriding importance of the quality of the surface discharge material are discussed. The development of a new surface discharge ceramic is described.

Effects of vacuum annealing treatment on microstructures and residual stress of AlSi10Mg parts produced by selective laser melting process

2016 ◽  
Vol 30 (19) ◽  
pp. 1650255 ◽  
Author(s):  
Tian Chen ◽  
Linzhi Wang ◽  
Sheng Tan
Keyword(s):  
Residual Stress ◽  
Tensile Strength ◽  
Selective Laser Melting ◽  
Vacuum Annealing ◽  
Annealing Treatment ◽  
Melting Process ◽  
Second Phase ◽  
Laser Melting ◽  
Heat Treated ◽  
Before And After

Selective laser melting (SLM)-fabricated AlSi10Mg parts were heat-treated under vacuum to eliminate the residual stress. Microstructure evolutions and tensile properties of the SLM-fabricated parts before and after vacuum annealing treatment were studied. The results show that the crystalline structure of SLM-fabricated AlSi10Mg part was not modified after the vacuum annealing treatment. Additionally, the grain refinement had occurred after the vacuum annealing treatment. Moreover, with increasing of the vacuum annealing time, the second phase increased and transformed to spheroidization and coarsening. The SLM-produced parts after vacuum annealing at 300[Formula: see text]C for 2 h had the maximum ultimate tensile strength (UTS), yield strength (YS) and elongation, while the elastic modulus decreased significantly. In addition, the tensile residual stress was found in the as-fabricated AlSi10Mg samples by the microindentation method.

Sign in / Sign up

Export Citation Format

Share Document