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The effects of growth environments on WS2 in electrocatalytic hydrogen evolution reaction

Journal of Physics and Chemistry of Solids 2024年 185卷

作者： Chang, Yung-Huang Huang, Chien-Sheng Chen, Yuan-Tsung Chiang, Chia-Yu Bachelor Program in Industrial Technology National Yunlin University of Science and Technology Yunlin Taiwan Department of Electronic Engineering National Yunlin University of Science and Technology Yunlin Taiwan Graduate School of Materials Science National Yunlin University of Science and Technology Yunlin Taiwan

Transition metal dichalcogenides (TMDs) recently have attracted much attention because of their outstanding catalytic activity, low cost, and earth abundance in the hydrogen evolution reaction (HER). Among these TMDs, MoS2 and WS2 are recognized as promising HER electrocatalysts and have been explored to be one of the candidates for replacing precious metals. In this work, the electrocatalytic activity of WS2 grown in Ar-only, Ar + H2, and ambient environments were studied, where the WS2 was synthesized by thermolysis from (NH4)2WS4 precursor. Different surface morphologies are shown under the different growth atmospheres. The structures of pure WS2, WS2 and WO3 mixed, and almost WO3 were prepared in different growth atmospheres of Ar-only, Ar + H2, and ambient environment, respectively. All the materials prepared in these different environments exhibit high crystalline characteristic. Especially, the pure WS2 grown in an Ar-only environment presents the preferred (103) lattice plane. The pure WS2 performs the best H2 evolution efficiency, indicating that high crystallinity and preferred (103) lattice plane could be relative to the electrocatalytic activity. The studies provide fundamental insight for further design and preparation of electrocatalysts, useful in the development of clean energy. © 2023 Elsevier Ltd

关键词： Electrocatalysts

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Terahertz Time-Domain Imaging for Radiotherapy Treatment Monitoring in Pancreatic Ductal Adenocarcinoma

Terahertz Time-Domain Imaging for Radiotherapy Treatment Mon...

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CLEO: Applications and Technology in CLEO 2024, CLEO: A and T 2024 - Part of Conference on Lasers and Electro-Optics

作者： Chakraborty, Debamitra Mills, Bradley N. Cheng, Jing Komissarov, Ivan Gerber, Scott Sobolewski, Roman Materials Science Graduate Program University of Rochester RochesterNY14627 United States Laboratory for Laser Energetics University of Rochester RochesterNY14623-1299 United States Department of Surgery University of Rochester Medical Center RochesterNY14642 United States Department of Electrical and Computer Engineering University of Rochester RochesterNY14627-0231 United States

ISBN: (纸本)9781957171395

Terahertz time-domain imaging was performed of stereotactic body radiotherapy-treated murine pancreatic ductal adenocarcinoma (PDAC) with a high spatial resolution. To generate 2D maps of the tissue samples, the refractive index and absorption coefficient were used as imaging markers extracted with the maximum a-posteriori probability (MAP) estimation algorithm. The results were then compared with the terahertz maps of untreated murine PDAC tissue samples and demonstrated that terahertz imaging can probe physical changes with high sensitivity in the tissue post treatment. © Optica Publishing Group 2024, © 2024 The Author(s)

关键词： Tissue

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Prediction of Potential-Dependent Kinetics for the Electrocatalytic Reduction of CO2to CO over Ti@4N-Gr

ACS Electrochemistry

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ACS Electrochemistry 2024年第3期1卷 328-337页

作者： Yousef A. Alsunni Abdulaziz W. Alherz Charles B. Musgrave Chemical Engineering Department King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia；Department of Chemical and Biological Engineering University of Colorado Boulder Colorado 80309 United States Department of Chemical Engineering College of Engineering and Petroleum Kuwait University Safat 13060 Kuwait Department of Chemical and Biological Engineering University of Colorado Boulder Colorado 80309 United States；Renewable and Sustainable Energy Institute University of Colorado Boulder Colorado 80309 United States；Materials Science and Engineering Program University of Colorado Boulder Colorado 80309 United States

Grand canonical density functional theory (GC-DFT) was employed to model the electrocatalytic reduction of CO2(CO2R) to CO by single titanium atom nitrogen-doped graphene, referred to as Ti@4N-Gr. Previous GC-DFT thermodynamic investigations have identified Ti@4N-Gr as a promising CO2R catalyst; however, no in-depth studies have examined it. In this study, we analyze activation energies of the elementary steps at various applied potentials in addition to thermodynamics of CO2R to CO catalyzed by Ti@xN-Gr defects. Reaction intermediates are predicted to be destabilized when Ti is coordinated to fewer N atoms. Based on reaction thermodynamics, Ti@4N-Gr and all defect configurations are predicted to be potentially promising catalysts for CO2R to CO at an applied potential of −0.7 VSHEwhile at −0.3 and −1.2 VSHEthe reaction is predicted to be hindered by relatively large grand free energy differences between intermediates. We propose a criterion to identify optimum applied potentials for CO2R to CO based on the potential of zero charge (PZC) of the reaction intermediates and the contention that the optimum applied potential for CO2R to CO lies in the rangePZC*CO

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Water Distillation-Advances, Challenges & Future Directions: A Brief Review

Water Distillation-Advances, Challenges & Future Directions:...

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IEEE International Conference on Emerging & Sustainable Technologies for Power & ICT in a Developing Society (NIGERCON)

作者： Remilekun R. Elewa Temitayo S. Ogedengbe Olawale Charles Ogunnigbo Sunday A. Afolalu Moses E. Emetere Adediran A.A Oluwatoyin Augustine Ojo Mechanical and Mechatronics Engineering Department Afe Babalola University Ado-Ekiti Nigeria Mechanical Engineering Department Nile University of Nigeria Abuja Department of Mechanical Science University Johannesburg South Africa Physics Program. Bowen University Iwo Osun State Nigeria Department of Metallurgical & Materials Engineering Federal University Ekiti Nigeria Department of Mechanical Engineering Science University of Johannesburg South Africa

ISBN: (数字)9798331542559

ISBN: (纸本)9798331542566

Every human being has the basic need for clean drinking water, however 1.1 billion people worldwide do not have access to it. While there are other methods for purifying water, including filtration, reverse osmosis, UV light, and carbon absorption, but distillation and boiling are the most dependable. Distillation is a vital method of purifying water, particularly in areas where tap water or water resources are unfit for human consumption without chemical or heating treatment. This review discusses the recent advances in water distillation. The techniques employed and challenges involved have also been discussed. Finally, the future direction of technology in this regard has been reviewed.

关键词： Humanities Heat treatment Reviews Purification Filtration Water heating Production Reverse osmosis Water resources Chemicals

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Highly Flexible Piezoelectric Pressure Sensor at Extremely High-Temperature Range Using Ultrawide-Bandgap III-N Thin Films

Highly Flexible Piezoelectric Pressure Sensor at Extremely H...

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IEEE Electron Devices Technology and Manufacturing Conference (EDTM)

作者： Nam-In Kim Miad Yarali Muhammad Aqib Jae-Hyun Ryou Department of Mechanical Engineering Texas Center for Superconductivity at UH Advanced Manufacturing Institute University of Houston USA Materials Science and Engineering Program University of Houston USA Department of Electrical and Computer Engineering University of Houston USA

Pressure monitoring in extreme conditions, such as in industrial, aerospace, and radioactive atmosphere, is crucial. Our focus is on developing and researching piezoelectric sensors that are highly flexible for detecting gas pressures at extremely high temperatures. We develop the flexible device using epitaxial III -nitride film, which is single-crystalline, by layer-transfer method. The sensor shows a sensitive and stable operation for extended periods. We use software simulation and relevant formulas to support our experimental findings.

关键词： Temperature sensors Pressure sensors X-ray scattering Sensor phenomena and characterization Software Semiconductor process modeling III-V semiconductor materials

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Cutting corners to suppress high-order modes in Mie resonator arrays

arXiv

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arXiv 2023年

作者： Haddadin, Zaid Khan, Shahrose Poulikakos, Lisa V. Department of Electrical & Computer Engineering UC San Diego United States Department of Mechanical & Aerospace Engineering UC San Diego United States Materials Science & Engineering Program UC San Diego United States

Mie resonators as lattice resonant metasurfaces have the capability to produce structural colour. However, design criteria for these metasurfaces are still being investigated. In this work, we numerically examine how the two-dimensional nanostructure shape in a lattice array affects the colorimetric response of the metasurface under linearly polarised light excitation. First, the transformation from a square-shaped to rectangle-shaped nanostructure array resulted in polarisation-sensitive metasurfaces with colorimetric outputs bound along a line on the CIE 1931 2-degree Standard Observer colour space. The bounds of the colorimetry line were tuneable to any desired chromatic range. Second, the removal of the corners in square- or rectangle-shaped nanostructures to create t-shaped nanostructure arrays displayed a dampening effect on the high-order resonance. Finally, we analytically determined that the colour saturation could increase when moving from rectangle-shaped to t-shaped nanostructure arrays. From these results, we present two design guidelines for lattice resonant metasurfaces: (1) Constructing the nanostructure to support fundamental resonances at different wavelengths enables two-colour-bound movement when excited by successive angles of linearly polarised light;(2) Removing portions of the nanostructure that only support high-order resonances dampens these modes while maintaining support for fundamental resonances. These results present first-principles guidelines for engineering nanoparticles in lattice resonant metasurfaces, offering a new toolbox for polarised-light sensing and colorimetric applications. Copyright © 2023, The Authors. All rights reserved.

关键词： Nanostructures

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Perspective on descriptors of mechanical behavior of cubic transition-metal carbides and nitrides

arXiv

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arXiv 2024年

作者： Kindlund, Hanna Ciobanu, Theodora Kodambaka, Suneel Ciobanu, Cristian V. Department of Materials Science and Engineering Virginia Polytechnic Institute State University BlacksburgVA24061 United States University of Notre Dame College of Arts and Letters Notre DameIN46556 United States Department of Mechanical Engineering and Materials Science Program Colorado School of Mines GoldenCO80401 United States

Cubic rocksalt structured transition-metal carbides, nitrides (TMC/Ns), and related alloys, are attractive for a wide variety of applications, notably as hard, wear-resistant materials. To-date, valence electron concentration (VEC) is used as a good indicator of stability and mechanical properties of these refractory compounds. In this perspective, we argue for the need of electronic descriptors beyond VEC to explain and predict the mechanical behavior of the cubic TMC/Ns. As such, we point out that descriptors that highlight differences between constituents, along with semi-empirical models of mechanical properties, have been underused. Additionally, it appears promising to partition VEC into contribution to ionic, covalent, and metallic bonds and we suggest that such partition could provide more insights into predicting mechanical properties in the future. Copyright © 2024, The Authors. All rights reserved.

关键词： Nitrides

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Process Optimization and Scaling of Molybdenum and Tungsten in Additive Manufacturing Techniques

SSRN

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SSRN 2024年

作者： Islam, Zahabul Kunkel, William Hatler, Caleb Thoma, Dan J. Mechanical and Manufacturing Engineering Program School of Engineering Bowling Green State University Bowling GreenOH43403 United States Alloy Design and Development Laboratory Department of Materials Science and Engineering University of Wisconsin MadisonWI53706 United States

Metal additive manufacturing processes pose a daunting challenge in defining optimal process parameters that yield porosity defect-free, dense parts. This is particularly true in refractory metals, where high melting temperatures limit process parameter windows. This present study investigates a dimensionless number analysis that has been derived through the Buckingham-PI theorem and demonstrates a robust correlation between process parameters and the density of the fabricated components. The introduction of this dimensionless number enables the initial estimation of process parameters without extensive modeling or experimentation. Additionally, a universal scaling law is proposed to enhance the translation of predicting process parameters for achieving an optimal density in as-built parts between different processing techniques. A combination of this proposed dimensionless number and scaling law offers process maps for tungsten and molybdenum with previously unknown process parameters. The universality of the proposed dimensionless number also demonstrates transferability, enabling the prediction of process parameters both for laser powder bed fusion and directed energy deposition systems. © 2024, The Authors. All rights reserved.

关键词： 3D printing

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Diving into COVID-19: Visualizing SARS-CoV-2 Patient Proteins using Liquid-Electron Microscopy

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Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada 2023年第1期29卷 662-664页

作者： Berry, Samantha DiCecco, Liza-Anastasia Gray, Jennifer Boylan, Jack Solares, Maria Kelly, Deborah F. Department of Biomedical Engineering Pennsylvania State University University Park PA United States Department of Materials Science and Engineering McMaster University Hamilton ON Canada Materials Research Institute Pennsylvania State University University Park PA United States Molecular Cellular Integrative Biosciences Graduate Program Huck Institutes of the Life Sciences Pennsylvania State University University Park PA United States Huck Institutes of the Life Sciences Pennsylvania State University University Park PA United States

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Effect of Sodium Dodecyl Sulfate and Hydrogen Peroxide on the Microstructure Evolution of Fiber-Reinforced Lightweight Geopolymer Composite

SSRN

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SSRN 2024年

作者： Alves, Cleidson Rosa Muller, Anderson Augusto Dal-Bó, Alexandre Gonçalves Bernandin, Adriano Michael Civil Engineering Department Federal Institute of Santa Catarina Santa Catarina Criciúma Brazil Graduate Program in Materials Science and Engineering University of the Extreme South of Santa Catarina Santa Catarina Criciúma Brazil Ceramic Materials Group United States

Lightweight geopolymers have the potential for innovative applications, such as low thermal conductivity material, pH regulator, adsorbent material, and lightweight concrete. However, these materials are often fragile due to their high porosity. In this study, the combined effect of sodium dodecyl sulfate (SDS) with hydrogen peroxide (H2O2) in the pore formation of a geopolymeric mortar reinforced with glass fiber and polypropylene fibers was investigated. The aim was to improve the distribution and morphology of pores, resulting in lower thermal conductivity. Lightweight mortars were produced using metakaolin, alkaline activators, and standardized sand. The innovation in this study lies in the incorporation of fibers as reinforcement in lightweight geopolymers and the microstructural changes resulting from the combination of the pore-forming agent (H2O2) with surfactant (SDS). The microstructural evolution in the fresh state, and density, porosity, and thermal conductivity in the hardened state were evaluated. As a result, the combined use of reinforcement fibers and control of pore volume is effective in the control of the microstructure of the mortar and, as a consequence, its thermal conductivity. SDS significantly contributes to foam stabilization, leading to improvements in thermal conductivity (0.15 W/m.K), Bulk density (1000 kg/m3), and a reduction in the average pore size. This suggests that these materials can be used for both thermal insulation and the construction of lightweight structural walls. © 2024, The Authors. All rights reserved.

关键词： Thermal insulation

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