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Accuracy of DFT computed oxygen-vacancy formation energies and high-throughput search of solar thermochemical water-splitting compounds

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Physical Review materials 2023年第6期7卷 065403-065403页

作者： Bianca Baldassarri Jiangang He Xin Qian Emanuela Mastronardo Sean Griesemer Sossina M. Haile Christopher Wolverton Graduate Program in Applied Physics Northwestern University Evanston Illinois USA Department of Materials Science and Engineering Northwestern University Evanston Illinois USA

The enthalpy change involved in metal oxide reduction is a key quantity in various processes related to energy conversion and storage and is of particular interest for computational prediction. Often this prediction involves the simulation of a high-temperature reduction process with a 0-K methodology like density functional theory (DFT), and it is not infrequent for the high temperature and 0-K stable crystal structures to differ. This introduces a conundrum with regard to the choice of crystal structure to utilize in the computation, with approaches in the literature varying and experimental validation remaining scarce. In this work, we address both the crystal structure conundrum and the experimental validation, and then apply the insights we gain to guide a high-throughput search for new materials for solar thermochemical water-splitting applications. By computing the DFT+U oxygen-vacancy formation energy (ΔEvf) of a selection of ABO3 compounds and comparing different crystal structures for each composition, we highlight the issues that arise when the structure utilized in the computation is dynamically unstable at 0 K, namely the presence of an artificial lowering of ΔEvf, and the lack of convergence of ΔEvf with cell size. We solve these limitations by identifying and employing a suitable surrogate dynamically stable structure. We then validate the predictive power of our calculations against appositely generated experimental measurements of reduction enthalpy for a series of Hubbard U values, finding an accuracy ranging between 0.2–0.6 eV/O. In light of such conclusions, we revise and expand a previous a high-throughput DFT study on ABO3 perovskite oxides. We provide a list of candidate STCH materials, highlight trends with redox-active cation and structural distortion, and identify Mn4+, Mn3+, and Co3+ as the most promising redox-active cations.

关键词： Energy applications First-principles calculations Hydrogen energy

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Basal and Edge Plane Activity of Two-Dimensional Dirac Semimetal Nite2 for Hydrogen Evolution Reaction

SSRN

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SSRN 2025年

作者： Cho, Suyeon Jeong, Seung Weon Kim, Jeong Hyo Lee, Seungyeon Yang, Heejun Lee, Sangheon Division of Chemical Engineering and Materials Science Graduate Program in System Health Science and Engineering Ewha Womans University Seoul03760 Korea Republic of Daejeon34141 Korea Republic of

. Nickel ditelluride (NiTe2), one of group-10 transition metal dichalcogenides, has shown intriguing surface states originating from its topological semi-metallicity. Here, we demonstrate abnormal catalytic activities at the NiTe2 surface for hydrogen evolution reaction (HER). We investigate the differences in catalytic activities at the basal and edge planes of NiTe2 using a micro-sized electrochemical reactor. The basal plane is found to be more active than the edge plane, resulting in a current density at the basal plane of NiTe2 exceeding 800 mA/cm2 with a small overpotential of -0.162 V. We conduct ab initio calculations to estimate the intrinsic catalytic activities of HER on the basal and edge planes of NiTe2. Interestingly, our calculation results suggest that the active sites at the edge plane are electrochemically more active than those at the basal plane. The discrepancy between the experimental measurements and theoretical predictions for the crystal-orientation-dependent HER activity highlights that the specialty of a topological semimetal plays a vital role in determining the HER rate for NiTe2 nanoparticle catalysts © 2025, The Authors. All rights reserved.

关键词： Hydrogen evolution reaction

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Using 4D-STEM to Map 3D Morphologies of 2D materials

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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 262-263页

作者： Mireles, Adan Shi, Chuqiao Park, Jeongwon Shin, Bongki Sung, Suk Hyun Ophus, Colin Hovden, Robert Kang, Kibum Han, Yimo Applied Physics Graduate Program Smalley-Curl Institute Rice University Houston TX United States Department of Materials Science and NanoEngineering Rice University Houston TX United States Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon South Korea Department of Materials Science and Engineering University of Michigan Ann Arbor MI United States National Center for Electron Microscopy Molecular Foundry Lawrence Berkeley National Laboratory Berkeley CA United States

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New insights into the hardening and pitting corrosion mechanisms of thermally aged duplex stainless steel at 475℃:A comparative study between 2205 and 2101 steels

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Journal of materials science & Technology 2022年第3期98卷 123-135页

作者： R.Silva G.S.Vacchi C.L.Kugelmeier I.G.R.Santos A.A.Mendes Filho D.C.C.Magalhães C.R.M.Afonso V.L.Sordi C.A.D.Rovere Munir Rachid Corrosion Laboratory Department of Materials EngineeringFederal University of São CarlosRodovia Washington Luis Km 23513565-905 São CarlosSPBrazil Engineering Modeling and Applied Social Sciences Center(CECS)Federal University of ABCAvenida dos Estados 500109210580 Santo AndréSPBrazil Federal University of São Carlos Graduate Program in Materials Science and EngineeringBrazil

In this study,the relationship between spinodal decomposition and the formation of Ni-rich clusters and G-phase in the ferrite on hardening and pitting corrosion of two thermally aged duplex stainless steels(DSSs)at 475℃was *** indicate that,for 2205 DSS,pitting corrosion behavior is influenced by the presence and size of G-phase precipitates for longer aging times,but this contribution is masked by the advanced stage of spinodal decomposition in the ferritic *** the other hand,for 2101 DSS,the formation of Cr-richer nitrides impairs pitting corrosion resistance more than spinodal decomposition.

关键词： Duplex stainless steel Spinodal decomposition G-phase precipitation Pitting corrosion Hardening

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Correlating the Ambient Conditions and Performance Indicators of the LoRaWAN via Surrogate Gaussian Process-Based Bidirectional LSTM Stacked Autoencoder

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IEEE Transactions on Network and Service Management 2023年第3期20卷 3413-3427页

作者： Bhat, Showkat Ahmad Huang, Nen-Fu Hussain, Imtiyaz Sajjad, Uzair National Tsing Hua University College of Electrical and Computer Science Hsinchu1300044 Taiwan National Tsing Hua University Department of Computer Science Hsinchu1300044 Taiwan National Taipei University of Technology Graduate Program in Energy and Opto-Electronic Materials Taipei10608 Taiwan National Taipei University of Technology Department of Energy and Refrigerating Airconditioning Engineering Taipei10608 Taiwan

LoRa's biggest advantage is its flexibility, which is the ability to increase or decrease data rate and range while decreasing or increasing sensitivity. Whenever propagation conditions change frequently, this function allows the spreading factor to be modified accordingly. Despite their efficiency and scalability, adaptive data rate algorithms ignore and fail to factor in the complex correlation between ambient weather parameters influencing the communication channel design. In this research, a Bayesian surrogate Gaussian process-based bidirectional LSTM stacked autoencoder model (BSGP-BLSTM-SAE) is proposed to estimate the channel performance indicators such as received signal strength indicator (RSSI) and signal-to-noise ratio (SNR) and to determine the correlation between the ambient weather conditions and performance indicators for the LoRaWAN network. Bayesian optimization algorithm has been used to optimize the hyper-parameters of the developed model. A LoRaWAN experimental multivariate time series dataset has been used for the evaluation of the developed model, which upon testing and validation produces high accuracy in predicting the channel performance indicators and ambient conditions of the experimental LoRaWAN network. The mean absolute error of the developed model was around 0.45. Thus, the proposed model can predict the link performance indicators and thereby assist in real-time optimization of the transmission parameters to enhance the network performance in LoRaWAN-based systems at different ambient conditions. © 2004-2012 IEEE.

关键词： Internet of things

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Characterizations of Ni-loaded lignite char catalysts and their performance enhancements to catalytic steam gasification of coal

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Journal of the Energy Institute 2022年 105卷 53-71页

作者： Tipo, Ronnachai Tippayawong, Nakorn Chaichana, Chatchawan Chimupala, Yothin Chaiklangmuang, Suparin Graduate Program in Industrial Chemistry Faculty of Science Chiang Mai University Chiang Mai50200 Thailand Department of Industrial Chemistry Faculty of Science Chiang Mai University Chiang Mai50200 Thailand Department of Mechanical Engineering Faculty of Engineering Chiang Mai University Chiang50200 Thailand Center of Excellence in Materials Science and Technology Faculty of Science Chiang Mai University Chiang Mai50200 Thailand Materials Science Research Center Faculty of Science Chiang Mai University Chiang Mai50200 Thailand

Catalyst characteristics such as specific surface area, porosity and active site play an essential role in catalyst design. Understanding of the characteristic functions in controlling catalyst activity is necessary for considering the catalyst application, especially the Ni-loaded lignite char catalyst, employed in catalytic steam gasification. In this work, the unmodified and five modified catalysts were used to study the effect of catalyst characteristics on their performance for catalytic steam gasification of coal in the two-stage fixed-bed reactor. The findings indicated that the fresh acid modified catalysts increased specific surface area and micropore formation, including the smaller Ni metal crystallite size, the decreasing of Ni metal nanoparticle size and the well-dispersed of Ni metal nanoparticles. Meanwhile, the fresh modified catalysts by the alkali and the combined alkali-acid treatments promoted mesopore formation. Enhancing catalytic steam gasification of coal, it was found that the mesoporosity of catalyst was the considerable initial characteristic for controlling the catalyst activity. The total gas yields of the mesoporous catalysts were in the range of 50.65–77.70 mmol/gVM,feed, while the total gas yields of the microporous catalysts were 43.82–55.34 mmol/gVM,feed. After catalyst testings, the specific surface areas and number of mesopores in the spent catalysts were increased by steam. Remarkably, these changing pore sizes affected the transformations of the isotherms (type I + II to type II) and the hysteresis loops (type H4 to type H3). Also, steam influenced the conversion of Ni metals to NiO, Ni(OH)2 and Ni2O3. For thermal property, all spent catalysts had high thermal stability. The modified catalysts could decrease carbon deposition more than the unmodified catalyst, which was an upside for catalyst reusability. © 2022 Energy Institute

关键词： Catalyst activity

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Elevated temperature-driven coordinative reconstruction of an unsaturated single-Ni-atom structure with low valency on a polymer-derived matrix for the electrolytic oxygen evolution reaction

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Nanoscale 2024年第15期16卷 7467-7479页

作者： Patil, Rahul Rajput, Anubha Matsagar, Babasaheb M. Chen, Norman C. R. Ujihara, Masaki Salunkhe, Rahul R. Yadav, Praveen Wu, Kevin C.-W. Chakraborty, Biswarup Dutta, Saikat Electrochemical Energy & Sensor Research Laboratory Amity Institute of Click Chemistry Research & Studies Amity University Noida India Department of Chemistry Indian Institute of Technology New Delhi India Department of Chemical Engineering National Taiwan University Taipei10617 Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taiwan National Taiwan University Taiwan Graduate Institute of Applied Science and Technology National Taiwan University of Science and Technology Taipei Taiwan Materials Research Laboratory Department of Physics Indian Institute of Technology Jammu India Synchrotron X-ray Facility Raja Ramanna Centre for Advanced Technology Rajendra Nagar Madhya Pradesh 452013 Indore India

A high-temperature pyrolysis-controlled coordination reconstruction resulted in a single-Ni-atom structure with a Ni-Nx-C structural unit (x = N atom coordinated to Ni). Pyrolysis of Ni-phen@ZIF-8-RF at 700 °C resulted in NiNP-NC-700 with predominantly Ni nanoparticles. Upon elevating the pyrolysis temperature from 700 to 900 °C, a coordination reconstruction offers Ni-Nx atomic sites in NiSA-NC-900. A combined investigation with X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and soft X-ray L3-edge spectroscopy suggests the stabilization of low-valent Niδ+ (0 −2 was achieved. The cell potential recorded with Pt(−)/(+)NiSA-NC-900/NF was much lower than that obtained for other cells, i.e., Pt(−)/NF and NF(−)/(+)NF, which enhances the potentials of low-valent NiSAs for insightful understanding of the OER. At a constant applied potential of 1.61 V (vs. RHE) for 12 h, an small increase in current for initial 0.6 h followed by a constant current depicts the fair stability of catalyst for 12 h. Our results offer an insightful angle into the OER with a coordinatively reconstructed single-Ni-atom structure at lower valency ( © 2024 The Royal Society of Chemistry.

关键词： Reaction kinetics

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Anomalous properties of spark plasma sintered boron nitride solids

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materials Today 2025年 86卷 42-51页

作者： Biswas, Abhijit Serles, Peter Alvarez, Gustavo A. Schimpf, Jesse Hache, Michel Kong, Jonathan Demingos, Pedro Guerra Yuan, Bo Pieshkov, Tymofii S. Li, Chenxi Puthirath, Anand B. Gao, Bin Gray, Tia Zhang, Xiang Murukeshan, Jishnu Vajtai, Robert Dai, Pengcheng Singh, Chandra Veer Howe, Jane Zou, Yu Martin, Lane W. Clancy, James Patrick Tian, Zhiting Filleter, Tobin Ajayan, Pulickel M. Department of Materials Science and Nanoengineering Rice University HoustonTX77005 United States Department of Mechanical & Industrial Engineering University of Toronto 5 King's College Road TorontoM5S 3G8 Canada Sibley School of Mechanical and Aerospace Engineering Cornell University IthacaNY14853 United States Department of Materials Science and Engineering University of California Berkeley94720 United States Department of Materials Science and Engineering University of Toronto 184 College St TorontoM5S 3E4 Canada Department of Physics and Astronomy McMaster University HamiltonL8S 4M1 Canada Applied Physics Graduate Program Smalley-Curl Institute Rice University HoustonTX77005 United States Department of Physics and Astronomy Rice University HoustonTX77005 United States Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley94720 United States

Hexagonal boron nitride (h-BN) is a brittle ceramic with a layered structure, however, recent experiments have suggested that inter-layer structural engineering could be key to new structural and functional properties. Here we report the scalable bulk synthesis of high-density crystalline h-BN solids, by using high-temperature spark plasma sintering (SPS) of h-BN powders, which show high values of mechanical strength, ductility, dielectric constant, thermal conductivity, and exceptional neutron radiation shielding capability. Through exhaustive characterizations we reveal that SPS induces non-basal plane crystallinity, twisting of layers, and facilitates inter-grain fusion with a high degree of in-plane alignment across macroscale dimensions, resulting in near-theoretical density and improved properties. Our findings highlight the importance of material design, via new approaches such as layer twisting and interlayer interconnections, to create novel ceramics with properties that could go beyond their intrinsic limits. © 2025

关键词： Ductility

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Vibrational entropies of oxygen vacancy formation in metal oxides

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Physical Review materials 2024年第5期8卷 055407-055407页

作者： Bianca Baldassarri Jiangang He Christopher Wolverton Graduate Program in Applied Physics Northwestern University Evanston Illinois 60208 USA Department of Materials Science and Engineering Northwestern University Evanston Illinois 60208 USA

Oxygen vacancies play a key role in many energy-related applications, and the investigation of the thermodynamic forces driving their formation across different materials can be tackled through the use of ab initio methods. In this context, however, computational studies targeting finite-temperature properties such as entropy remain scarce. Wider-ranging studies are of interest to deepen the understanding of the role of the entropy of oxygen vacancy formation and its different components in processes like the ones involved in solar thermochemical hydrogen (STCH) production, and to investigate the existence of common trends and differences between materials. In this work, we use density functional theory and harmonic phonon calculations to compute the vibrational entropy of oxygen vacancy formation (ΔSvib) for 10 different metal oxide compounds. The computation is carried out by taking the difference between the vibrational entropy of a vacancy-containing and a pristine structure, while the entropic contribution from the final gaseous state of the oxygen lost from the material is accounted for separately with a gas entropy term. We first examine the temperature dependence of ΔSvib and highlight the presence of an initial peak around room temperature, followed by a steady decrease resulting from the presence of an additional O atom (the one becoming vacant) in the defect-free structure. We then inspect the atomic contributions to ΔSvib, and highlight similarities and differences between compounds. Finally, we consider other significant sources of entropy, and find ΔSvib to provide a smaller, yet non-negligible, contribution to the total entropy of vacancy formation. We also compare the temperature dependence of ΔSvib to that of the gas entropy, and show that the two largely counterbalance each other at high temperatures.

关键词： Entropy Hydrogen production Density functional theory

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Preparation of LFP-based cathode materials for lithium-ion battery applications

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materials Today: Proceedings 2022年 65卷 2347-2350页

作者： Suttison, Suchanat Pengpat, Kamonpan Intatha, Uraiwan Fan, Jinchen Zhang, Wei Eitssayeam, Sukum Master's Degree Program in Materials Science Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Graduate School Chiang Mai University Chiang Mai Thailand Department of Physics and Materials Science Faculty of Science Chiang Mai University Thailand Center of Innovative Materials for Sustainability School of Science Mae Fah Luang University Chiang Rai 57100 Thailand School of Materials and Chemistry University of Shanghai for Science and Technology Shanghai 200093 China Department of Engineering Mechanics Dalian University of Technology Dalian 116024 China

Lithium-ion batteries (LIB) have developed into the mainstream power source of energy storage devices due to their advantages: high power density, high power, long service life, and less pollution. This materials development for LFP batteries was considered successful in synthesizing powder. Here we show that three synthesis conditions were performed. LFP doped NiO, NMC, and (NH4)2HPO4 were synthesized by the nitrogen gas flow method. LFP-doped NiO was burned at 600 °C and 700 °C for five h. NMC doped with LFP burned at 550 °C for five h, and NMC-doped LFP and (NH4)2HPO4 were burned at 550 °C and 600 °C for five h. The structure and morphology of the material were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). © 2022

关键词： Lithium-ion batteries

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