芘基共轭微孔聚合物用于锂离子电池电极材料性能研究

共轭微孔聚合物由于其高的比表面积、优良的物理化学稳定性以及沿分子链延伸的共轭结构等特点,使其在锂离子电池电极材料方面具有巨大的应用前景.本工作以四溴芘和对苯二硼酸为构建单元,通过Suzuki偶联反应合成了具有高比表面积的芘基共轭微孔聚合物PyDB,并研究了其作为锂离子电池电极材料的电化学性能.当PyDB用作锂离子电池正极材料时,在50 mA·g^-1的电流密度下,放电容量达到163 mAh·g^-1,即使在3000 mA·g^-1的电流密度下仍具有62 mAh·g^-1的可逆容量,在100 mA·g^-1的电流密度下循环300次仍具有167 mAh·g^-1的容量.当该聚合物用作负极材料时,在50 mA·g^-1电流密度下的放电容量达到495 mAh·g^-1,在200 mA·g^-1的电流密度下循环300次,仍具有245 mAh·g^-1的容量.PyDB优异的电化学性能主要归因于其延伸的共轭结构和高比表面积的多孔结构,大的共轭结构有利于分子链的掺杂反应和电子传导,高比表面积的多孔结构有利于提供大量的活性位点并促进离子的迁移.     

P-Bi2Te3/MXene超结构钾离子电池负极制备及其性能

Bi₂Te₃钾离子电池负极存在结构不稳定性和电化学反应动力学缓慢问题。本研究在手风琴状MXene基底上生长棒状Bi₂Te₃,随后利用P掺杂制备了高性能P-Bi₂Te₃/MXene超结构。这种新型负极具有丰富的Te空位和良好的自适应特性,展现出优异的循环稳定性(在0.2 A·g^-1电流密度下200次循环后可逆容量为323.1 mAh·g^-1)和出色的倍率能力(20 A·g^-1时可逆容量为67.1 mAh·g^-1)。动力学分析和非原位表征表明,该超结构具有优异的赝电容特性、出色的K⁺离子扩散能力以及可逆的嵌入反应和转化反应机理。     

一种新型的碳复合钼掺杂的钒氧化物纳米线钠离子电池正极材料

近年来,由于锂资源逐渐紧缺而导致其成本增加,锂离子电池发展受到了限制. 作为一个有潜力的替代者,有着相似电化学机制且成本较低的钠离子电池则发展迅速. 但由于钠离子与锂离子相较有着更大半径,在钠离子脱嵌过程中,对大多数电极材料的晶体结构破坏严重. 因此,开发新型电极材料对钠离子电池的进一步发展尤为重要. 其中,层状钒氧化物作为正极材料被广泛研究. 在这项工作中,作者基于钒氧化物,引入钼元素并与碳复合,首次设计合成了一种新型的碳复合钼掺杂的钒氧化物纳米线电极材料,并获得了优良的电化学性能（在50 mA•g^-1的电流密度下,最高放电比容量达135.9 mAh•g^-1,并在循环75次后仍有82.6mAh•g^-1的可逆容量,容量保持率高达71.8%;在1000mA•g^-1的高电流密度下循环并回到50mA•g^-1后,可逆放电比容量仍能回复至111.5mAh•g^-1）. 本工作的研究结果证明,这种具有超大层间距的新型碳复合钼掺杂的钒氧化物纳米线是一种非常有潜力的储钠材料,并且我们的工作为钠离子电池的进一步发展提供了一定的理论基础.     

还原氧化石墨烯/TiO2复合材料在钠离子电池中的电化学性能

二氧化钛(TiO₂)作为有前景的钠离子电池负极材料, 具有良好的循环稳定性, 但由于其导电率较低, 而导致容量和倍率性能不佳限制了其实际应用. 本文采用喷雾干燥技术制备了氧化石墨烯/纳米TiO₂复合材料(GO/TiO₂), 通过热处理获得还原氧化石墨烯/TiO₂复合材料(RGO/TiO₂). 电化学测试结果表明, 还原氧化石墨烯改性的RGO/TiO₂复合材料的电化学性能得到显著提升, RGO含量为4.0%(w)的RGO/TiO₂复合材料在各种电流密度下的可逆容量分别为183.7 mAh·g^-1 (20 mA·g^-1), 153.7 mAh·g^-1 (100 mA·g^-1)和114.4 mAh·g^-1 (600mA·g^-1), 而纯TiO₂的比容量仅为93.6 mAh·g^-1 (20 mA·g^-1), 69.6 mAh·g^-1 (100 mA·g^-1)和26.5 mAh·g^-1 (600mA·g^-1). 4.0%(w) RGO/TiO₂复合材料体现了良好的循环稳定性, 在100 mA·g^-1电流密度下充放电循环350个周期后, 比容量仍然保持146.7 mAh·g^-1. 同等条件下, 纯TiO₂电极比容量只有68.8 mAh·g^-1. RGO包覆改性极大提高了TiO₂在钠离子电池中的电化学嵌钠/脱钠性能. RGO包覆改性技术在改进钠离子电池材料性能中将有很好的应用前景.     

铜钱状二硫化钒的制备及储钠性能研究

钠离子电池因地壳中丰富的钠资源以及金属钠与金属锂之间具有相似的物化性质等特点,成为后锂时代电池的候选者之一,然而较大的钠离子半径影响了其体系的动力学性能及离子迁移速率,因此寻找合适的电极材料成为其发展的关键.二硫化钒作为过渡金属硫属化合物,具有类石墨烯的层状结构,为钠离子的储存提供了足够的空间,同时其出色的导电性能也为其作为高性能钠离子电池的电极材料提供了保证.利用水热法与超声剥离法,可控制备出三种堆叠密度不同的铜钱状二硫化钒（VS₂-Long、VS₂-Middle、VS₂-Short）,并将其用于储钠性能研究.结果表明,堆叠程度最低的VS₂-Short因其形貌结构特点而拥有较多的活性位点及较高结构稳定性,在100 mA·g^－1的电流密度下,循环300圈后容量高达410 mAh·g^－1;电流密度为2000 mA·g^－1,可逆容量仍高达333 mAh·g^－1.此外,还研究了二硫化钒作为钠离子电池电极材料的储能机制,通过非原位X射线粉末衍射（XRD）及透射电子显微镜（TEM）观测发现：放电过程中,电压在2.5～1.0 V发生嵌钠反应生成Na_xVS₂,之后逐渐开始转化反应生成Na₂S和V;充电时Na₂S和V转化生成Na_xVS₂,并最终脱钠生成VS₂,即在0.2～2.5 V间VS₂表现为嵌入转化的储钠机制.     

空心碳球负载二硫化硒复合材料作为锂离子电池正极材料

制备了一种空心碳球负载二硫化硒(SeS₂@HCS)复合材料作为锂离子电池正极材料。通过扫描电子显微镜(SEM),X射线衍射(XRD)以及氮气吸脱附测试(BET)等对产物形貌、组成和结构进行了表征。实验结果显示,采用模板法结合化学聚合法可以合成形貌均一、单分散的空心碳球;其直径约为500 nm,壁厚约为30 nm。进一步采用熔融灌入法可以得到空心碳球负载二硫化硒复合材料。将所制备复合材料组装成电池进行电化学性能测试,与原始二硫化硒块体材料相比,SeS₂@HCS复合材料具有更高的初始容量(100 mA·g^-1电流密度下,初始放电容量为956 mAh·g^-1)和更长的循环寿命(100 mA·g^-1电流密度下,循环200圈),同时显示出更优异的倍率性能。研究结果表明该复合材料是一种具有应用前景的新型锂离子电池正极材料。     

ZnCl2活化玉米秸秆炭化物的制备及其储锂性能研究

以玉米秸秆为原料,经高温煅烧制备了玉米秸秆炭化物（C1）和ZnCl₂活化玉米秸秆炭化物（C2）。利用扫描电子显微镜（SEM）、N₂等温吸-脱附测试和恒电流充放电对材料进行结构、电化学性能分析。结果表明：C2具有较大的比表面积（425.06 m₂·g^-1）和丰富的孔道结构;电流密度为100 mA·g^-1时,C1和C2的首次放电和充电比容量分别为540.2 mAh·g^-1, 277.2 mAh·g^-1和1 156.0 mAh·g^-1, 517.6 mAh·g^-1; 600 mA·g^-1电流密度下循环300次后,C2的放电比容量可保持在379.8 mAh·g^-1, C2具有较高的可逆比容量和良好的循环稳定性。     

碳空心球/硫复合材料制备和电化学性能研究

采用PMMA为模板制备碳空心球材料,并以碳空心球材料为导电骨架与硫材料复合制得碳空心球/硫复合材料. SEM和TEM照片显示,硫材料能均匀地填充在碳空心球的孔道和腔体内部. 采用恒电流充放电测试碳空心球/硫复合电极的电化学性能. 结果表明,在100 mA·g^-1、500 mA·g^-1、1 A·g^-1、2 A·g^-1 和5 A·g^-1电流密度下,碳空心球/硫复合电极可逆放电容量分别为1145 mAh·g^-1、824 mAh·g^-1、702 mAh·g^-1、586 mAh·g^-1和395 mAh·g^-1,呈现出较优异的倍率循环寿命.     

碳包覆纳米SnO2中空纤维的制备及电容性能

采用同轴静电纺丝法制备了碳包覆纳米SnO₂中空纤维超级电容器电极材料.利用X射线衍射(XRD)、拉曼光谱、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和比表面积分析仪(BET)对材料进行表征.结果表明,纤维呈现中空形貌,平均直径为1 μm; SnO₂颗粒均匀分布于碳壳结构中,平均粒径为3-15 nm.材料的比表面积为565 m²·g^-1.在三电极体系中,当电流密度为0.25 A·g^-1时,电极材料的比容量达397.5 F·g^-1;在1.0A·g^-1电流密度下,充放电循环3000次后比容量仍保持为初始值的88%.在对称型双电极体系中,电流密度为0.25 A·g^-1时,电极材料的比容量达162.0 F·g^-1,在1.0 A·g^-1电流密度下,充放电循环3000次后比容量仍保持为初始值的84%.     

高倍率球形锂离子电池正极材料LiNi0.5Co0.2Mn0.3O2的制备及其电化学性能研究

采用碳酸盐共沉淀-高温固相法制备得到了颗粒平均尺寸约5 μm振实密度为2.1 g·cm^-3的均匀微球形高镍LiNi_0.5Co_0.2Mn_0.3O₂材料.X射线衍射（XRD）分析和透射电镜（TEM）结果表明这种微球状LiNi_0.5Co_0.2Mn_0.3O₂材料具有完善的层状α-NaFeO₂结构,过渡金属层原子呈[√3×√3]R30°排布.电化学性能测试结果证实了该材料具有优异的循环稳定性和高倍率性能.具体而言,在2.7~4.3 V,1C下循环100次后的放电比容量为150 mAh·g^-1,容量保持率为94.6%,在30C的超高倍率下,放电比容量还能达到96 mAh·g^-1.同时,该材料的储能能力也非常突出,在0.1C时比能量密度为687.83 Wh·kg^-1（体积能量密度为1444.45 Wh·L^-1）,在30C时仍达335.27 Wh·kg^-1（体积能量密度为704.07 Wh·L^-1）,非常有潜力应用于商业化高能量密度锂离子电池.     

Ti-48Al-2M~1-2M~2(M~1=Nb,V;M~2=Mn,Cr,V)合金电子结构

用紧束缚能带计算方法(EHT)研究了标题多元合金的能带及电子结构。发现少量的多种元素在γ-TiAl中掺杂,对合金中电荷分布的影响,具有单种元素掺杂的叠加性;选择适当的合金元素就能达到多种掺杂的性能互补。多种元素掺杂能更有效地使成键电子云趋势于球形化,Peierls力均称为化,有利于增加γ-TiAl合金的塑性和变形性。     

《电化学分析传感》专辑序言

《电化学分析传感》专辑序言 电化学分析传感是一种基于界面电荷相互作用的测量方法,具有高灵敏、响应快、无标记等本征优势. 该方法的核心思路是将待测对象构建成为化学电池的某一部分,通过测量界面电子转移或电荷重排过程中产生的电信号响应,如电池电位、电流、电导、电量变化,对待测目标进行定性定量动态地检测、监测或表征. 　　近年来,伴随着测量仪器性能和数据处理方法的持续提高与优化,电化学分析传感研究前沿热点越来越多地关注到纳米尺度界面上的瞬态电荷相互作用、动态电荷传输机制,特别是发展限域空间内的单体纳米电化学信号放大、传输、记录、解析新模式和新策略. 其中,单体电化学分析,如单颗粒碰撞法等,不仅可以得到常规宏观测量的单一平均结果,同时还能描绘出所有不同颗粒结构与性能的完整分布,揭示少量但关键的电化学活性位点和反应机理;而纳米限域电化学分析,如纳米孔道协同测量等,则能通过限域效应有效延长亚稳态中间体的结构寿命,灵敏识别不同待测单体间的细微理化性质差异及其动态变化过程. 此外,电分析方法也更多地与谱学、成像等技术联用,对界面电化学过程进行原位、实时、在线表征,以期揭示纳米界面的电荷传递和能量转化的化学本质. 进而指导设计构建高灵敏电化学传感器,实现在疾病的早期检测、能源转换的高效率用、水体环境污染的有效治理等国家战略性产业中的广泛应用. 　　本专辑围绕电化学分析传感新方法与新技术,收录了在相关研究领域具有丰富经验积累和影响力的团队所撰写的21篇相关研究进展的综述文章和研究论文（分成两期出版,分别包含10篇和11篇）. 希望借助此专辑的出版,能使广大读者更好地了解当前电化学测量领域的研究现状、研究趋势和存在的问题及挑战,推动我国下一代电化学精准分析技术和高效传感应用的进一步发展. 　　最后,对本专辑的所有作者、审稿人及编辑部工作人员的辛勤工作和付出表示由衷的感谢！     

Herbal Composition LI73014F2 Alleviates Articular Cartilage Damage and Inflammatory Response in Monosodium Iodoacetate-Induced Osteoarthritis in Rats

The aim of this study was to determine the anti-osteoarthritic effects of LI73014F2, which consists of Terminalia chebula fruit, Curcuma longa rhizome, and Boswellia serrata gum resin in a 2:1:2 ratio, in the monosodium iodoacetate (MIA)-induced osteoarthritis (OA) rat model. LI73014F2 was orally administered once per day for three weeks. Weight-bearing distribution and arthritis index (AI) were measured once per week to confirm the OA symptoms. Synovial membrane, proteoglycan layer, and cartilage damage were investigated by histological examination, while synovial fluid interleukin-1β level was analyzed using a commercial kit. Levels of pro-inflammatory mediators/cytokines and matrix metalloproteinases (MMPs) in the cartilage tissues were investigated to confirm the anti-osteoarthritic effects of LI73014F2. LI73014F2 significantly inhibited the MIA-induced increase in OA symptoms, synovial fluid cytokine, cartilage damage, and expression levels of pro-inflammatory mediators/cytokines and MMPs in the articular cartilage. These results suggest that LI73014F2 exerts anti-osteoarthritic effects by regulating inflammatory cytokines and MMPs in MIA-induced OA rats.     

Teaching of Analytical Chemistry in Polish Universities

The importance of Analytical Chemistry in the modern world is continually increasing. There are a lot of reasons: the need for environmental monitoring, food quality control, human health, industrial production quality control, nanotechnologies, material science; these are only some of the areas where analysts are indispensable. Analytical Chemistry, or rather Chemical Analytics, should be treated on a par with the three fundamental chemical courses: Inorganic Chemistry, Organic Chemistry, and Physical Chemistry. Analytical Chemistry, as an individual course or courses, is lectured in 52 Polish universities, including the Academy of Medicine and Academy of Life Sciences (agriculture and related). All these universities were already introduced in the Bolonia Process, The European Credit Transfer System (ECTS) points, and three steps of education: Bachelor's degree (at universities of technology–Engineer's degree), Master's degree, and Doctoral Studies. Analytical Chemistry exists on all levels of teaching. On the first level, Bachelor's degree, the program of Analytical Chemistry contains the basic knowledge, so called classical Analytical Chemistry: gravimetric analysis, electrogravimetry, acid-base titration, oxidation-reduction titration, precipitation titration, complexometric titration, quality assurance, and quality control of results (2–3 h of lecture, 5 h of laboratory, and 1 h of seminar). During the second level (Master's degree) the program contains more developed analytical techniques: gas and liquid chromatography, spectrophotometric methods, electrochemical methods, elemental analysis, etc. The lecture courses at universities depend on the specific specialization, and there are a variety of different courses according to the need of specialization programs. The Bachelor's (engineer's) projects (diploma theses) are very often prepared in the field of Analytical Chemistry. The same occurs with Doctoral Studies; very often, students choose subject matters connected with Analytical Chemistry. This is why each year we have about 100 doctoral candidates in the field of Analytical Chemistry. The laboratories of Polish universities are well equipped with specialized apparatuses, but are strongly dependent on the university's profile and the size of the university. Students can participate in the scientific research carried on by the didactic staff, especially when completing diploma theses or doctorates. Some of them are performing studies and theses abroad, in the frame of the LLP ERASMUS Program. From our department, each year, about 10–12 students complete their Analytical Chemistry theses abroad. It promotes the European dimension and improves the quality of education by encouraging innovation in education.     

Miguel Valcárcel, University of Córdoba

The Analyst profiles Miguel Valcárcel, Full Professor of Analytical Chemistry in the University of Córdoba and recipient of the Solvay Prize for Chemistry (1996) and the Robert Boyle Medal of the Analytical Division of the Royal Society of Chemistry (2004).     

Richtlinien für die Präsentation der Methoden bei der Publikation von Rechenergebnissen – Teil B: Semiempirische Berechnung der elektronischen Struktur von Molekülen

Die Übersetzung basiert auf den „Guidelines for Presentation of Methodological Choices in the Publication of Computational Results. B. Semiempirical Electronic Structure Calculations“ des Subcommittee on Theoretical Chemistry der Commission on Molecular Structure and Spectroscopy der Physical Chemistry Division der International Union of Pure and Applied Chemistry, veröffentlicht in Pure Appl. Chem. 2000 , 72, 1149–1452. Das Original wurde von James J. P. Stewart (Stewart Computational Chemistry, Colorado Springs, USA) für die Veröffentlichung vorbereitet.     

Richtlinien für die Präsentation der Methoden bei der Publikation von Rechenergebnissen – Teil A: Ab‐initio‐Berechnung der elektronischen Struktur von Molekülen

Die Übersetzung basiert auf den „Guidelines for Presentation of Methodological Choices in the Publication of Computational Results. B. Semiempirical Electronic Structure Calculations“ des Subcommittee on Theoretical Chemistry der Commission on Molecular Structure and Spectroscopy der Physical Chemistry Division der International Union of Pure and Applied Chemistry, veröffentlicht in Pure Appl. Chem. 2000 , 72, 1149–1452. Das Original wurde von James J. P. Stewart (Stewart Computational Chemistry, Colorado Springs, USA) für die Veröffentlichung vorbereitet.     

Surface and capillary effects on detection limits of chromophoric analytical systems

Sorption and capillary effects of a solid supporter in microqualitative analysis can be studied using suitable chromophoric analytical systems. The identification limits (LI) of various analytical tests have been determined applying several types of microqualitative supporters of ion-exchange resin group and filter paper. The differences in LI values can be explained by the differences in phase volumes and areas in which the analytical reaction product (AR) accumulates. Accumulation of AR by sorption and division of AR by capillary spreading have the opposite effects on LI values. When AR is a colored complex the place of its formation in the identification test has also significant effect on LI values. However, it is difficult to correlate the sorption of AR on a supporter to the conditions of its formation in the solution and to the ionic character of the complex. Also, no relationship between simple physical properties of supporters and detection limits developed. The experimental techniques applied (spot test, resin spot test, ring test) affect the sensitivity of the microqualitative analysis significantly.     

A schematic overview of the historical evolution of Analytical Chemistry

The historical evolution of Analytical Chemistry is briefly discussed as related to the progress of Chemistry within the 16–19th centuries under the leadership of Paracelsus, Boyle, Lavoisier and Dalton. A clear distinction is made between chemical analysis (up to the end of the 19th c.) and today’s Analytical Chemistry, paying close attention to a number of aspects and consequences related to the chemical revolution which took place at the overlap of the 18–19th c. which resulted in the quantification of Chemistry, causing increasing development and improvement of the chemical metrology which was an essential factor for Chemistry to acquire a scientific dimension and to become more specialised during the 19th century. A panoramic view of the whole development is presented by resorting to the inclusion of a number of synoptical tables outlining the stepwise progress of Chemistry, chemical analysis and Analytical Chemistry within the five last centuries taking into consideration the main protagonists involved as well as the experimental means, techniques and methodologies used and/or developed. Received: 20 February 1996 / Accepted: 21 May 1996     

基于热控电极的电致化学发光传感器的研究进展

电致化学发光（ECL）检测技术因其具有无需激发光源、仪器简单、灵敏度高、选择性好等特点,被广泛应用于环境分析、生物分析等领域. 温度是影响ECL的主要因素之一,在传统的ECL传感器中大多是通过溶液整体加热的方法来控制温度,这种方法操作繁琐,且溶液中的热不稳定性物质及易挥发性物质容易受到影响,因此电极很少工作在最适宜的温度下. 热控电极技术可以只提高电极表面温度,而维持溶液的整体温度不变,使用起来具有很好的便利性. 作者课题组首次将热控电极引入到ECL传感器的构建中,由于电极表面和溶液之间存在一定的温度梯度,因此可以引发强制对流,从而加快物质的扩散和对流速率;电极表面温度的升高还可以进一步提高电极表面物质的电化学反应速率,这两方面的共同作用提高了ECL检测的灵敏度. 同时,利用热控电极可以解决整体加热所引起的背景信号升高,挥发性、热不稳定性物质易受温度影响等问题,而且通过电极加热的方法可去除电极表面的污染物,从而提高ECL检测的重现性. 本文综述了近年来基于热控电极技术的ECL传感器的研究进展,主要介绍了热控电极的加热方式、电极种类以及热控电极在ECL中的应用等,并分析了该技术在实际应用中面临的主要问题,对该技术未来的发展趋势进行了展望.