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Activating lattice oxygen of two-dimensional MnXn-1O2 MXenes via zero-dimensional graphene quantum dots for water oxidation

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Science China materials 2022年第11期65卷 3053-3061页

作者： Yiyuan Ma Yurong An Zhuo Xu Laifei Cheng Wenyu Yuan Science and Technology on Thermostructural Composite Materials Laboratory School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Solidification Processing School of Material Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Lab for Advanced Energy TechnologyInstitute for Advanced Energy MaterialsSchool of Materials Science and EngineeringShaanxi Normal UniversityXi’an 710119China Key Laboratory of Macromolecular Science of Shaanxi Province Key Laboratory of Applied Surface and Colloid ChemistrySchool of Chemistry&Chemical EngineeringShaanxi Normal UniversityXi’an 710062China

The poor oxygen evolution reaction(OER)activity of two-dimensional(2 D)transition metal carbides(MXenes)is a major obstacle to their application in highperformance water splitting and fuel cells due to the high energy barriers for the absorption of ***,we demonstrate that the lattice oxygen of M_(n)X_(n-1)O_(2)MXenes can be activated by 0 D graphene quantum dots(GQDs),thereby activating the OER via the lattice-oxygen oxidation mechanism(LOM)instead of the conventional adsorbate evolving *** pH-dependent OER activity of M_(n)X_(n-1)O_(2)@GQDs and ^(18)O isotope-labelling experiments with time-of-flight secondary-ion mass spectrometry(TOF-SIMS)provide the direct evidence of ***,the activated lattice oxygen amount can be controlled by the *** as-prepared 0 D/2 D Ti_(3)C_(2)O_(2)@GQDs heterostructure delivers a highly reduced overpotential of 390 mV(bare Ti_(3)C_(2)O_(2):530 mV)at a benchmark current density of 10 mA cm^(-2).Through optimizing the thickness and the additional conductive substrate,the overpotential at 10 mA cm^(-2)decreases to 250 mV,while the Tafel slope is reduced to 39 mV dec^(-1);these values indicate the as-prepared heterostructure is superior to the state-of-the-art MXene-based OER *** work provides a new strategy to enhance the OER activity of M_(n)X_(n-1)O_(2)and extends the application of LOM from perovskite to MXenes.

关键词： graphene quantum dots lattice-oxygen activation oxygen evolution reaction water splitting heterostructure

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Ceramizable Cf/BPR composites with enhanced oxidation resistance up to 1670 °C

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Ceramics International 2025年

作者： Li, Junguo Zhao, Chenhan Jiang, Feng Zhang, Shiquan Yang, Suohui Xiang, Qianqian Li, Meijuan zhang, Jian Shen, Qiang School of Material Science and Engineering Wuhan University of Technology Wuhan430070 China School of Chemistry Chemical Engineering and Life Science Wuhan University of Technology Wuhan430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China

Ceramizable carbon fiber/boron-modified phenolic resin (Cf/BPR) composites are cost-effective and suitable for fabricating large-scale components, making them vital for thermal protection systems in aerospace vehicles. However, their thermal resistance requires further improvement. This study investigates the modification of Cf/BPR composites using ZrSi2, Al, and mica to enhance their thermal resistance. High-temperature static oxidation and oxyacetylene ablation tests are conducted to evaluate their high-temperature performance. The role of each filler on oxidation resistance is discussed. The results reveal that when ZrSi2 is added at 33.75 phr, Al at 3.75 phr, and mica at 5 phr, the prepared composite exhibits a flexural strength of 56 MPa after 20 min of static oxidation at 1600 °C, with excellent protection of the carbon fibers. After oxidation at 1670 °C, the flexural strength remains at 45 MPa, despite some degree of carbon fiber ablation. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Carbon fibers

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Highly Enhanced Electro-Catalytic Behavior of an Amide Functionalized Cu(Ii) Coordination Polymer on Oer at Large Current Densities

SSRN

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SSRN 2024年

作者： Afaq, Sheereen Ashiq, Faheem Shoukat, Wseem Malik, Wasif Mahmood Ahmed Ismail, Muhammad Ghafoor, Abdul Ashraf, Zohaib Sajjad, Muhammad Verpoort, Francis Chughtai, Adeel Hussain Institute of Chemical Sciences Bahauddin Zakariya University Multan60800 Pakistan Pakistan Moscow117198 Russia State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Center for Chemical and Material Engineering Wuhan University of Technology Wuhan430070 China

Extensive utilization of fossil fuels has led to their swift exhaustion, causing an escalating energy dilemma and significant environmental apprehensions. This situation has spurred advancement of sustainable energy conversion systems. Electrochemical water splitting is viewed as a capable method for generating hydrogen and oxygen intended for diverse electrochemical energy apparatus. A proficient, multifunctional electro-catalyst capable of facilitating both OERs) and HERs is of paramount importance. In this work, we report Cu-MOF electro-catalyst synthesized via the solvothermal route engaging OER activity using nickel foam (NF) in a 1 M KOH solution. Several analytical techniques were used to investigate the electro-catalysts BET, PXRD, FTIR and oxidation states. The water-splitting evaluation of the LOCOM-1 demonstrated exceptional oxygen activity concerning OER (oxygen evolution reaction), showcasing to extent a current density of 10 mAcm-2 a reduced of 286 mV over potential. Additionally, it exhibited a diminished onset potential of 1.37V attributable towards a decreased Tafel slope of 44.50 mVdec-1, and a proton couple electron transfer (PCET) channel that is stable over an extended period of time (1000 cycles of cyclic voltammetry and 40 hours of chronoamperometry). Therefore, this current endeavour might offer a new prospect or pathway for exploring the OER (Oxygen Evolution Reaction). © 2024, The Authors. All rights reserved.

关键词： Potassium hydroxide

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Smart Insole: Stand-Alone Soft 3-Axis Force Sensing Array in a Shoe

Smart Insole: Stand-Alone Soft 3-Axis Force Sensing Array in...

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IEEE SENSORS

作者： Jian Gao Zihao Pu Ruixin Qiu Ying Li Xiulun Yin Kieran Morton Sadan Wani Justin Wyss Michael Steszyn Ryusuke Ishizaki Fumiya Hamatsu Takeshi Ohsato John D.W. Madden Department of Electrical & Computer Engineering Advanced Material Processing Engineering Laboratory University of British Columbia Vancouver Canada i-generator Portland USA Frontier Robotics Honda R&D Co. Ltd Saitama Japan

Foot plantar force monitoring has been explored using in-shoe soft insole measurements for application in diabetic foot and to assess footwear performance. Sensors are impractical for regular use due to bulky electronics and short battery life. They typically lack shear sensing. A soft flexible and custom configurable 3-axis capacitive sensing array is demonstrated through a customizable arrangement of 16-shear and normal force taxels completely imbedded in a shoe insole that wirelessly updates at 50 $\mathrm{n}_{2}$ . A patterned silicone dielectric mounted on a flex printed circuit board enables normal and shear sensitivities of 19.9 and 2.8 $\text{kPa}^{-1}$ . The 20 $\text{mW}$ power consumption includes transmission of data to a nearby mobile device, which is satisfied for more than 50 hours using a built-in 350 mAh LiPo battery. Operation in a shoe is demonstrated.

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Electrical Properties and Degradation Behavior of Bnt-Bt-Ln Ceramics

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SSRN 2023年

作者： Xu, Qi Yan, Xuerui He, Xin Dong, Shengde Ma, Luxiang Hai, Chunxi Zhou, Yuan Liu, Hanxing College of Materials and Chemistry & Chemical Engineering Chengdu University of Technology Chengdu610059 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Material Science and Engineering Wuhan University of Technology Wuhan430070 China

Dielectric capacitors are widely used in pulse power systems, electric vehicles, aerospace and defense technology as critical electronic components. Due to the miniaturization and diversification of electronic components, higher requirements are put on the electrical properties and the service life of dielectric capacitors. In this paper, the phase structure, microstructure, dielectric, ferroelectric and failure behavior of (1-x)(Bi0.5Na0.5TiO3-BaTiO3)-xLiNbO3 (BNT-BT-LN, x = 0.01, 0.03, 0.05, 0.07, 0.10) lead-free ceramics were investigated. All the samples exhibited perovskite phase with no secondary impurity. With increasing LiNbO3 concentration, the average grain size gradually increases from 0.78 μm to 1.75 μm. For the composition x = 0.07, the temperature coefficient of capacitance (TCC150°C) was lower than 15% in the range of 35 °C - 400 °C with moderate permittivity (Εr 150 °C = 2050) and low dielectric loss (tanδ150 °C = 0.005). The RC constant is above 19.3 s up to 245 °C. Through Highly Accelerated Life Test (HALT), the mean time to failure (TTF) empirical formula for BNT-BT-LN dielectrics is established. It indicates that the degradation of the insulation resistance process is caused by the electromigration of oxygen vacancies and the TTF is predicted to reach 4.67×106 h at 7 kV/mm and room temperature. © 2023, The Authors. All rights reserved.

关键词： Lithium compounds

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Broadband metasurface bandpass filter with wide angular stability for the Ku-band

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Optik 2024年 311卷

作者： Li, Nan Zhao, Jingcheng Xie, Yongjun Wang, Dong Cheng, Yongzhi School of Electronic Information Engineering Beihang University Beijing100191 China Aerospace Institute of Advanced Material & Processing Technology Beijing100074 China School of Information Science and Engineering Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education Wuhan University of Science and Technology Hubei Wuhan430081 China Hubei Longzhong Laboratory Xiangyang441000 China

Broadband spatial spectral filters have consistently been in high demand due to their diverse and extensive applications across numerous fields in the past decades. In this paper, a broadband metasurface (MS) bandpass filter (BPF) with wide angular stability was proposed and investigated at Ku band. The unit-cell of the proposed MS BPF is consisted of the cross-shape structure (CSS) sandwiched with two layer identical four-square-patches (FSPs) and dielectric substrates. Finite element method (FEM) simulation indicates that the designed MS BPF has distinctive broadband transmission coefficient of over −3 dB from 12.75 GHz to 16.8 GHz with a relative bandwidth of 27.4 %, which is basically consistent with equivalent circuit model (ECM) calculation. The physical mechanism underlying the proposed MS BPF is elucidated through the introduction of impedance matching theory, electric field and surface current analysis. Further numerical simulation has confirmed that the designed broadband MS BPF exhibits valid performance across a wide spectrum of incident angles, encompassing both transverse electric (TE) and transverse magnetic (TM) polarizations. Finally, a prototype has been fabricated for measurements, and the proposed design has been validated through comprehensive analysis of simulated and measured results. Due to its excellent transmission properties, the proposed MS BPF shows potential application in such as radar, remote sensing, and satellite communication. © 2024 Elsevier GmbH

关键词： Bandpass filters

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Microstructure and Properties of Copper/Graphene Composites Prepared Via Powder Hot Extrusion

SSRN

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SSRN 2024年

作者： Chen, Kaili Dong, Jialiang Qiu, Cheng Luo, Zongqiang Zhang, Datong Guangdong Key Laboratory for Advanced Metallic Materials Processing and Forming National Engineering Research Center of Near-net-shape Forming for Metallic Materials South China University of Technology Guangzhou510640 China College of Material Science and Engineering Guizhou Minzu University Guizhou550025 China

Cu/Gr composites have been reported to have high mechanical properties and electrical conductivity, but some of the preparation methods are difficult to execute for industrial production. In this study, Cu/Gr composites were successfully prepared by direct hot extrusion without sintering, and then microstructure, mechanical properties, and electrical conductivity were investigated. Graphene and copper powder were mixed using ultrasonic vibration combined with a V-type mixer. The addition of graphene enhances the mechanical properties of the material, making it have a high electrical conductivity of 94%IACS, and the yield strength and tensile strength are 208 MPa and 233 MPa, respectively. © 2024, The Authors. All rights reserved.

关键词： Graphene

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Selective utilization of formaldehyde stabilizing additive and methoxy groups in lignin for the production of high-carbon-number arenes

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Chinese Journal of Catalysis 2025年第1期68卷 356-365页

作者： Lin Dong Zhiqiang Fang Qianbo Yuan Yong Fan Yong Yang Ping Wang Shixiong Sheng Yanqin Wang Zupeng Chen Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsCollege of Chemical EngineeringNanjing Forestry UniversityNanjing 210037JiangsuChina State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640GuangdongChina Feili Chemical Engineering(Zhejiang Suichang)Co.Ltd. Suichang 323316ZhejiangChina Dehua TB New Decoration Material Co. LtdHuzhou 313200ZhejiangChina Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterResearch Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Many strategies have been proposed to produce arenes from lignin as liquid fuel ***,the development of these methods is limited by the low yield of products,low atom utilization,and inefficient lignin ***,we develop an energy-efficient synthetic method for the production of high-carbon-number arenes from sustainable lignin with a total yield of 23.1 wt%.Particularly,high carbon number arenes are obtained by fully utilizing the formaldehyde stabilizing additive and the methoxy group in *** process begins with the reductive depolymerization of formaldehyde-stabilized lignin,followed by transmethylation between lignin monomers over Au/Nb_(2)O_(5) catalyst,and the Ru/Nb2O5-catalyzed *** work demonstrates the potential of value-added arenes production directly from lignin.

关键词： Lignin Arene Transmethylation Hydrodeoxygenation Liquid fuel additive

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Enhanced bioactivity and interfacial bonding strength of Ti3Zr2Sn3Mo25Nb alloy through graded porosity and surface bioactivation

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Journal of materials Science & Technology 2022年第5期100卷 137-149页

作者： Sen Yu Zhe Yu Dagang Guo Hui Zhu Minghua Zhang Jianye Han Zhentao Yu Yemin Cao Gui Wang State Key Laboratory for Mechanical Behavior of Materials School of Material Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Shaanxi Key Laboratory of biomedical metallic materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016China Orthopedics Oncology Institute of Chinese PLA Tangdu HospitalAir Force Medical UniversityXi’an 710038China Shanghai Hospital of Integrated Traditional Chinese and Western Medicine Shanghai University of Traditional Chinese MedicineShanghai 201203China Centre for Advanced Materials Processing and Manufacturing(AMPAM) The University of QueenslandSt LuciaQLD 4072Australia

The gradient porous Ti3Zr2Sn3Mo25Nb(TLM)alloy rods were fabricated through sintering the alloyed powder to a solid *** porous sample was then modified by a Micro Arc Oxidation(MAO)treatment in an electrolyte containing calcium and phosphate,a hydrothermal treatment enabled secondary microporous hydroxyapatite(HA)coating,and a further bone morphogenetic protein-2(BMP-2)loading treatment through immersion and *** treatment led to an orderly secondary microporous coating containing HA nano-particles and evenly distributed BMP-2 in the porous *** a result,osteoblasts could adhere and grow well on the coatings with a high cell adhesion rate and cell functional *** in-situ shear testing indicated that the interfacial strength had been enhanced *** of the bond formation and osseointegration with the titanium implant is attributed to increased surface area for the cell to attach,creating voids for the cell to grow in,and activating titanium surface by introducing bioactive ingredients such as HA and BMP-2.

关键词： Graded porosity titanium Secondary microporous Bioactivity Ti3Zr2Sn3Mo25Nb alloy Interface binding strength

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Deformation behaviors of four-layered U-shaped metallic bellows in hydroforming

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Chinese Journal of Aeronautics 2020年第12期33卷 3479-3494页

作者： Jing LIU Zhiyong LV Yang LIU Lanyun LI Key Laboratory of Materials Processing Engineering School of Material Science and EngineeringXi'an Shiyou UniversityXi'an 710065China Key Laboratory of Advanced Manufacture Technology for Automobile Parts(Chongqing University of Technology) Ministry of EducationChongqing 400054China Bime Bremen Institute of Mechanical EngineeringMAPEX Center for Materials and ProcessingUniversity of BremenBremen 28359Germany

Because of the complex constraint effects among layers in multi-layered metallic bellows hydroforming,the stress concentration and defects such as wrinkling and fracture may easily *** is a key to reveal the deformation behaviors in order to obtain a sound *** on the ABAQUS platform,a 3 D-FE model of the four-layered U-shaped metallic bellow hydroforming process is established and validated by *** stress and strain distributions,wall thickness variations and bellow profiles of each layer in the whole process,including bulging,folding and springback stages,are *** deformation behaviors of bellows under different forming conditions are *** is found that the wall thinning degrees of different layer vary after hydroforming,and is the largest for the inner layer and smallest for the outer *** folding stage,the wall thinning degree of the crown point increases lineally,and the difference among layers increases as the process *** displacements of the crown point decrease from the inner layer to the outer *** springback,the U-shaped cross section changes to a tongue shape,the change of convolution pitch is much larger than the change of convolution height,and the springback values of the inner layer are smaller than the outer *** increase in the internal pressure and die spacing cause the maximum wall thinning degree and springback *** changing of process parameters,bellows with deep convolution are easily encountered wall thinning during hydroforming and convolution distortion after *** research is helpful for precision forming of multi-layered bellows.

关键词： Deformation behaviors Four-layered U-shaped bellow Hydroforming Numerical simulation Springback

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