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2D CaWO4 nanosheets derived from scheelite minerals for enhanced electrocatalysis in oxygen evolution reaction

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Science China Chemistry 2025年

作者： Qing Sun Yongxiang Sun Yan Dong Hong Zhong Hongbo Zeng National&Local United Engineering Laboratory for New petrochemical Materials&Fine Utilization of Resources College of Chemistry and Chemical EngineeringHunan Normal University Department of Chemical and Materials Engineering University of Alberta college of Chemistry and Materials Engineering Hunan University of Arts and Science college of Chemistry and Chemical Engineering Central South University

Scheelite （CaWO4） mineral holds promise as a cost-effective and efficient catalyst for the oxygen evolution reaction （OER）crucial in renewable energy ***,challenges such as limited active site exposure and low electrocatalytic performance need *** this work,we have fabricated two-dimensional （2D） CaWO4nanosheets from scheelite minerals via a straightforward ultrasonic exfoliation method and evaluated their efficacy as OER *** to scheelite powders,these 2D nanosheets exhibited superior crystallinity and a 1.26-fold increase in electrochemical surface area,promoting active site *** 2D CaWO4nanosheet electrode demonstrated outstanding OER catalytic performance,achieving a current density of 20 mA/cm2at an overpotential of 290 m V in alkaline conditions,which was lower than that of bulk CaWO4electrodes （～340 mV）.Density functional theory calculations attributed this enhanced catalytic performance to moderate adsorption of oxygenated intermediates （*OH,*O,and*OOH） on the W sites of 2D *** situ electrochemical atomic force microscopy tests also confirmed the catalytic enhancement by 2D CaWO4nanosheets during *** findings demonstrate the potential of affordable and abundant mineral resources in advancing electrochemical catalysts for oxygen evolution,highlighting their broader application in sustainable energy technologies.

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Fabrication and Mechano-sensing Characteristics of Bending Polypyrrole Actuator

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Journal of Wuhan University of technology(Materials Science) 2025年第1期 240-245页

作者：陈金友胡巍 School of Automotive Engineering Hunan Financial & Industrial Vocational-technical College college of Mechanical and Electrical Engineering Hunan Agricultural University

To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is *** of the essential goals is to examine the mechanical characteristics of the actuator in the presence of various combinations of process parameters,combined with the orthogonal test method of "four factors and three levels".The bending and sensing characteristics of actuators of various sizes are methodically examined using a self-made bending polypyrrole *** functional relationship between the bending displacement and the output voltage signal is established by studying the characteristics of the actuator sensor subjected to various degrees of *** experimental results reveal that the bending displacement of the actuator tip almost exhibits a linear variation as a function of length and *** the voltage reaches 0.8 V,the bending speed of the actuator tends to be ***,the mechanical properties of the self-assembled polypyrrole actuator are verified by the design and fabrication of the microgripper.

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Preparation and Mechanical Behavior of Mg-Based Bulk Metallic Glasses and their Matrix Composite

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Journal of Wuhan University of technology(Materials Science) 2012年第3期27卷 555-559页

作者：司颐 Department of Applied Chemistry Liaoning Petrochemical Vocational and Technology College

Mg87-xCuxDy13（x=22,27,32） bulk metallic glasses （BGMs） with a diameter of 6-8 mm and in-situ Mg phase reinforced Mg70Cu17Dy13 BMG matrix composite with a diameter of 3 mm have been prepared by copper mould casting. The glass forming ability （GFA） of Mg-Cu-Dy alloys have been investigated by differential scanning calorimetry （DSC） and X-Ray diffraction （XRD） and tne mechanical properties have been measured. Results show that Mg87-xCuxDy13（x=22,27,32） alloys in the Mg-Cu-Dy alloy system exhibit excellent GFA, and Mg60Cu27Dy13 alloy has the largest GFA among these alloys. And In-situ Mg phase reinforced Mg70Cu17Dy13 BMG matrix composite exhibits some work hardening and a high fracture compressive strength of 702.38 MPa and some plastic strain of 0.81%. The improvement of the mechanical properties is attributed to the fact that the Mg phase distributed in the amorphous matrix of the alloy has some effective load bearing and plastic deformation ability to restrict the expanding of shear bands and cracks and produce its own plastic deformation.

关键词： Mg-Cu-Dy alloys glass forming ability composites mechanical properties

Unveiling localized electronic properties of ReS2 thin layers at nanoscale using Kelvin force probe microscopy combined with tip-enhanced Raman spectroscopy

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Chinese Physics B 2023年第11期32卷 598-603页

作者：罗宇苏伟涛张娟娟陈飞武可曾宜杰卢红伟 School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China hunan petrochemical vocational technology college Yueyang 414011China college of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018China

Electronic properties of two-dimensional(2D) materials can be strongly modulated by localized strain. The typical spatial resolution of conventional Kelvin probe force microscopy(KPFM) is usually limited in a few hundreds of nanometers, and it is difficult to characterize localized electronic properties of 2D materials at nanoscales. Herein, tip-enhanced Raman spectroscopy(TERS) is proposed to combine with KPFM to break this restriction. TERS scan is conducted on ReS2bubbles deposited on a rough Au thin film to obtain strain distribution by using the Raman peak shift. The localized contact potential difference(CPD) is inversely calculated with a higher spatial resolution by using strain measured by TERS and CPD-strain working curve obtained using conventional KPFM and atomic force microscopy. This method enhances the spatial resolution of CPD measurements and can be potentially used to characterize localized electronic properties of 2D materials.

关键词： few layer ReS2 tip enhanced Raman spectroscopy local strain Kelvin probe force microscopy

La-EDTA coated Fe_3O_4 nanomaterial:Preparation and application in removal of phosphate from water

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Journal of Environmental Sciences 2013年第2期25卷 413-418页

作者： Jiao Yang Qingru Zeng Liang Peng Ming Lei Huijuan Song Boqing Tie Jidong Gu Department of Environmental Science&Engineering Hunan Agricultural University School of Metallurgical Science and technology Central South University hunan Perochemical vocational technology college

La-EDTA-Fe3O4 was prepared by a chemical co-precipitation method. The magnetic composite was characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （FT-IR）. Furthermore, the adsorption properties of La-EDTA-Fe3O4 toward phosphate in water were investigated. The uptake rate of phosphate in water by La-EDTA-Fe3O4 was 3-1000 times than that of EDTA-Fe3O4, and reached 97.8% at 7 hr. The adsorption process agreed well with the Freundlich model and kinetics studies showed that the adsorption of phosphate proceeds according to pseudo second-order adsorption kinetics. The maximum removal rate was achieved at pH 6.0-7.0. The La-EDTA-Fe3O4 had good adsorption properties and could be separated well from aqueous solution by a permanent magnet. Therefore, this nanomaterial has potential application for the removal of phosphate from large water bodies.

关键词： La-EDTA-Fe3O4 phosphate magnetic materials

A Mild and Rapid Synthesis of （Z）-β-Sulfonyl Enoates from Sodium Sulfinates and Propargyl Esters

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Chinese Journal of Chemistry 2016年第12期34卷 1245-1250页

作者： Jun Jiang Huaxu Zou Niannian Yi Ruijia Wang Hao Zhang Lixin Lan Jiannan Xiang State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University Changsha Hunan 410082 China hunan Chemical vocational technology college Zhuzhou Hunan 412000 China

Water-promoted sulfonylation of propargyl esters leading to highly regioselective and stereoselective formation of （Z）-β-sulfonyl enoates in excellent yields, by a simple, mild, rapid and environmentally benign rea... 详细信息

关键词： sodium sulfinates propargyl esters green reaction (Z)-β-sulfonyl enoates

Method for triangular fuzzy multiple attribute decision making based on two-dimensional density operator method

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Journal of Systems Engineering and Electronics 2024年第1期35卷 178-185页

作者： LIN Youliang LI Wu LIU Gang HUANG Dong School of Economics and Management Hunan Institute of Science and TechnologyYueyang 414000China hunan vocational college for Nationalities Yueyang 414000China School of Information Science and Engineering Hunan Institute of Science and TechnologyYueyang 414000China

Aiming at the triangular fuzzy(TF)multi-attribute decision making(MADM)problem with a preference for the distribution density of attribute(DDA),a decision making method with TF number two-dimensional density(TFTD)operator is proposed based on the density operator theory for the decision maker(DM).Firstly,a simple TF vector clustering method is proposed,which considers the feature of TF number and the geometric distance of ***,the least deviation sum of squares method is used in the program model to obtain the density weight ***,two TFTD operators are defined,and the MADM method based on the TFTD operator is ***,a numerical example is given to illustrate the superiority of this method,which can not only solve the TF MADM problem with a preference for the DDA but also help the DM make an overall comparison.

关键词： fuzzy decision making clustering density operator multi-attribute decision making(MADM)

A High-Accuracy Curve Boundary Recognition Method Based on the Lattice Boltzmann Method and Immersed Moving Boundary Method

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2533-2557页

作者： Jie-Di Weng Yong-Zheng Jiang Long-Chao Chen Xu Zhang Guan-Yong Zhang hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment Hunan University of Science and TechnologyXiangtan411201China School of Mechanical Engineering Hunan Chemical Vocational Technology CollegeZhuzhou412000China

Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved bound-aries is vital in aircraft design,ocean,and construction ***,current methods such as Lattice Boltzmann(LBM)and the immersion boundary method based on solid ratio(IMB)have limitations in identifying custom curved ***,IBM based on velocity correction(IBM-VC)suffers from inaccuracies and numerical ***,this study introduces a high-accuracy curve boundary recognition method(IMB-CB),which identifies boundary nodes by moving the search box,and corrects the weighting function in LBM by calculating the solid ratio of the boundary nodes,achieving accurate recognition of custom curve *** addition,curve boundary image and dot methods are utilized to verify *** findings revealed that IMB-CB can accurately identify the boundary,showing an error of less than 1.8%with 500 ***,the flow in the custom curve boundary and aerodynamic characteristics of the NACA0012 airfoil are calculated and compared to *** showed that IMB-CB yields lower lift and drag coefficient errors than IBM-VC,with a 1.45%drag coefficient *** addition,the characteristic curve of IMB-CB is very stable,whereas that of IBM-VC is *** the moving boundary problem,LBM-IMB-CB with discrete element method(DEM)is capable of accurately simulating the physical phenomena of multi-moving particle flow in complex curved *** research proposes a new curve boundary recognition method,which can significantly promote the stability and accuracy of fluid-solid interaction simulations and thus has huge applications in engineering.

关键词： Fluid-solid interaction curve boundary recognition method Lattice Boltzmann method immersed moving boundary method

Chorus-Driven Outer Radiation Belt Electron Dynamics at Different L-Shells

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Chinese Physics Letters 2010年第12期27卷 219-222页

作者：张赛肖伏良 hunan Science and technology Industrial vocational and Technical college Xiangtan 411207 School of Physics and Electronic Sciences Changsha University oF Science and Technology Changsha 410004

Energetic outer radiation belt electron phase space density （PSD） evolution due to interaction with whistler-mode chorus at different L-shells is investigated by solving the diffusion equation including cross diffusion terms. It is found that the difference of diffusion rates for different L-shells occurs primarily at pitch angles 0°-50° and around 90°. In particular, diffusion rates for L = 6.5 are found to be 5-10 times larger than that for L = 3.5 at these pitch angles. In the presence of cross terms, PSD for - MeV electrons after 24h decreases by about 25, 12, 10 and 8 times at L = 3.5, 4.5, 5.5 and 6.5 near the loss cone, and increases by about 55, 45, 30 and 20 times at larger pitch angles, respectively. After 24 h, the ratios between - MeV electron PSDs from simulations without and with cross diffusion at L = 3.5, 4.5, 5.5 and 6.5 are about 350, 600, 800 and 800 near the loss cone, and become 5, 5.5, 6.5 and 8 at pitch angle 90°, respectively. These results demonstrate that neglect of cross diffusion generally results in the overestimate of PSD, and the cross diffusion plays a more significant role in the resonant interaction between chorus waves and outer radiation belt electrons at larger L.

关键词： RADIATION belts ELECTRONS NUCLEAR shell theory PHASE space (Statistical physics) DENSITY HEAT equation MOLECULAR dynamics