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《大学化学》2021,36(6)
以“碱金属的结构与性能及其在锂离子电池中的应用”为例说明元素化学课堂教学中的方法,旨在引导学生学习与掌握碱金属的结构与性质的基础知识,使学生对碱金属元素在锂离子电池中应用产生兴趣,领悟无机化学相关的科学前沿的新知识、新规律和新概念,培养学生的创新意识。同时,分组讨论碱金属的结构与化学性质之间关系及其在新能源领域中的应用,组织学生深入到开展相关研究的课题组,在教师指导下开展锂离子电池电极材料制备与表征以及器件组装和电化学性能测试,并根据获得的结果复习课堂中讲授的知识。进一步,鼓励和推进学生开展碱金属在新能源器件中应用的本科生科研训练,在科学研究中应用无机化学基础知识,实现课本知识与科学实践相衔接。 相似文献
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实现钠离子电池等储能设备的大规模应用对于能源的可持续发展以及完成“碳达峰碳中和”目标具有重要意义.开发高性能的负极材料可提升钠离子电池的能量密度和循环稳定性,是实现钠离子电池大规模应用的关键性因素.中空碳材料因其独特的结构而具有优异的倍率性能与循环稳定性,作为钠离子负极材料具有广阔的应用前景.本文从多角度出发,综合评述了中空碳材料的合成方法,以及其形貌、杂原子修饰策略与储钠性能之间的关系,并对其未来发展方向进行了展望. 相似文献
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近年来,随着温室效应即全球变暖引发的环境问题越来越严峻,因此,CO2转化与再生引起了科学界的广泛关注,其中备受关注的是电催化CO2还原。而二维材料电催化剂可以将CO2还原为高附加值的多碳化合物,但催化剂的合成设计以及理论研究有待更多的研究。从发现石墨烯开始,二维材料的其他超薄层状结构的广泛研究逐渐出现。本文重点综述了石墨烯、MXenes、金属氧化物、二维MOFs和过渡金属硫族化合物等二维材料的构建以及其CO2还原电催化技术应用方面的最新进展,并简要的介绍了二维材料的分类和制备方法。讨论了电催化CO2还原的基本原理以及反应途径。指出了二维材料电催化剂面临的机遇和挑战,旨在对二维材料电催化剂的合成以及应用提供一些新的思路。 相似文献
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作为零维碳基发光纳米材料,碳点是对现有发光纳米材料的重要补充. 精准控制粒径及表面结构对实现碳点的性质调控及其应用至关重要. 本文介绍了本课题组在利用电化学方法研究荧光碳点方面的进展. 重点展示了利用电化学方法实现对碳点粒径的控制,对表面氧化程度的调节以及对其发光机理的研究. 电化学方法可对只有几纳米厚度的材料表面进行有效的控制,可操作性强且经济环保. 通过对碳点的粒径及表面的调控,作者也进一步揭示了碳点的发光与表面结构的相关性. 这些工作为碳点的合成及其性质调控提供了可循的规律,有利于推动碳点在生物医生成像、传感检测、催化及能源转化等领域的应用. 相似文献
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本文对一类重要的ⅥB族金属叁键化合物R_2M_2(CO)_4(R为环戊二烯基及类环戊二烯基)近年来的研究成果进行了综述,综述重点是这类化合物的官能团M≡M参键的化学活性,全文包括R_2M_2(CO)_4的合成及结构,M≡M叁键与亲核试剂、与碳-碳重键,与氧或与金属羰基物等试剂的反应及其应用。 相似文献
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层状双金属氢氧化物(LDH)基光催化剂在太阳能燃料生产领域的研究进展 总被引:1,自引:0,他引:1
半导体光催化剂吸收太阳光分解水制氢或还原CO2,实现了太阳能燃料生产,不仅可获取清洁、可再生、高热值的太阳能燃料,还能有效减少CO2的排放.层状双金属氢氧化物(LDHs)是一类基于水镁石结构的二维阴离子黏土矿物材料,具有独特的层状结构、主体层金属阳离子可调性、客体阴离子可交换、多维结构和可分层等优势,在CO2还原、光电催化水产氧及光解水制氢等领域研究广泛,有望成为新型半导体光催化材料.但单纯LDHs载流子迁移率低和电子空穴复合率高,在太阳辐射下的量子效率非常低.因此,研究人员采用缺陷控制、设计多维结构或偶联不同类型半导体构建异质结等方法,获得高能量转换效率的LDH基光催化剂.本文首先总结了传统光催化剂的优缺点及其能带分布,阐述了LDHs的六个主要方面特性,包括主体层板金属阳离子可调性、客体阴离子插层、热分解、记忆效应、多维结构特征及分层,进而提出LDH基光催化材料在增强反应物吸附活化、扩宽吸光范围、抑制光生载流子与空穴复合三个方面的改性策略.然后,分析了LDH光催化剂的光催化水解产氢反应机理,并从材料结构与性能的关联,概述LDH基复合光催化剂(金属硫化物LDH复合材料、金属氧化物LDH复合材料、石墨相氮化碳LDH复合材料)、三元LDH基光催化剂及混合金属氧化物光催化剂在水分解制氢领域的研究进展.最后,分析了LDH光催化还原CO2反应机理,归纳石墨相氮化碳复合LDH材料、MgAl-LDH基复合光催化剂、CuZn-LDH光催化剂及其它半导体系列LDH的结构特点和在还原CO2领域的研究进展.尽管LDH基光催化剂研究取得了一定的进展,但是对LDH的结构调控及其光催化机理仍需进一步探索,光催化活性位点、不同组分之间的协同作用和界面反应机理还有待进一步研究.未来LDH在光催化领域的应用可以微观尺度调控和宏观性能为导向设计,进一步研究不同组分的协同效应、界面反应及材料组成对物理化学性质的影响,不断完善LDH基光催化剂的理论系统和开发其应用潜能. 相似文献
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Chang-Il Ahn Yong Min Park Jae Min Cho Dong Hyun Lee Chan-Hwa Chung Bong Gyoo Cho Jong Wook Bae 《Catalysis Surveys from Asia》2016,20(4):210-230
CO hydrogenation to hydrocarbons through Fischer–Tropsch synthesis (FTS) reaction is one of the promising chemical processes, which can convert alternative feedstocks such as natural gas or biomass into synthetic fuels. The FTS reaction has received many attentions due to a limited petroleum resource with an increased demand for using alternative carbon sources such as stranded gas or shale gas. Some proper synthetic methods of an effective FTS catalyst having a larger active metal surface area and a lower deactivation rate are the most important issues for a long-term operation. Therefore, some ordered mesoporous materials (OMM) have been widely investigated in the field of CO hydrogenation using some heterogeneous catalysts. The present brief review paper summarized the various preparation methods of the ordered mesoporous materials for the possible applications of FTS reaction with a lower deactivation rate and a higher catalytic performance. The applications of the ordered mesoporous cobalt oxides for FTS reaction are briefly introduced and the ways to improve a structural stability even under reductive CO hydrogenation conditions by using efficient pillaring materials as well as by preparing mixed metal oxides. A higher catalytic activity of the ordered mesoporous cobalt oxide was also verified in a multi-channel fixed-bed compact reactor having the intersected interlayers of micro-channel heat exchanger. The thermal stability of ordered mesoporous cobalt-based catalysts was mainly affected by a structural stability which can easily remove the heavy hydrocarbons from the inner surfaces. 相似文献
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金属–有机框架(MOFs)材料具有比表面积较大、孔径可调、制备容易、结构与功能多样性等优势,被广泛应用于电化学能源转化与储存领域。其中独特的核壳结构材料由于表面修饰的作用往往更能表现出核内与壳层的协同作用。本文介绍了具有核壳结构MOFs作为锂离子电池负极材料的发展现状,并重点综述其衍生物(多孔碳材料、金属氧化物、金属硫/硒化物以及金属/金属氧化物)的制备方法以及在锂离子电池负极中的应用。MOFs通过高温煅烧或改变化学反应条件的方法,可制备出结构可调的传统无机电极材料并表现出更优异的电化学性能。最后总结了核壳结构MOFs材料作为锂电负极材料存在的问题和挑战,并提出可能的解决途径和未来的应用前景。 相似文献
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As one of the naturally abundant elements,carbon can present in different molecular structures(allotropes) and thus lead to various physical/chemical properties of carbon-based materials which have found wide applications in a variety of fields including electrochemistry,optical,adsorption and catalysis,etc.On the other hand,its different allotropes also endow carbon-based materials with various morphostructures,which have been recently explored to prepare oxides and zeolites/zeotypes with tailored structures.In this review,we mainly summarize the recent advances in using carbon materials as hard templates to synthesize structural materials.Specifically,we focus on the development in the synthetic strategies,such as endotemplating,exotemplating approaches and using carbon materials as chemical reagents for the synthesis of metal carbides or nitrides,with an emphasis laid on the control of morphostructure.Meanwhile,the applications of the obtained materials will be highlighted,especially,in the field of heterogeneous catalysis where enhanced performances have been achieved with the materials derived from carbon-templated methods. 相似文献
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Two-dimensional photocatalytic materials have potential applications in the fields of environmental purification and energy conversion owing to their rich surface active sites, unique geometric structures, adjustable electronic structures, and good photocatalytic activities. At present, the main two-dimensional photocatalytic materials include metal oxides, metal composite oxides, metal hydroxides, metal sulfides, bismuth-based materials, and non-metallic photocatalytic materials. The absorption of photons in bulk materials or nanoparticles is often limited by the transmittance and reflection at the grain boundary, while the two-dimensional structure can provide a large specific surface area and abundant surface low-coordination atoms to obtain more UV visible light. In addition, the smaller atomic thickness of two-dimensional photocatalytic materials can shorten the carrier migration distance. Thus, in two-dimensional photocatalytic materials, the carriers generated in the interior migrate to the surface faster than that in the bulk materials, which can reduce the recombination of photogenerated carriers and facilitate the photocatalytic reaction. For the surface redox reaction, the two-dimensional structure can provide more abundant surface-active sites to accelerate the reaction process. Additionally, when the thickness is reduced to the atomic scale, the escape energy of atoms is relatively small, thereby increasing the surface defects, which is helpful for the adsorption and activation of target molecules. Thus, the synthesis methods and performance enhancement strategies of two-dimensional photocatalytic materials have been developed rapidly. The former strategies mainly focus on the adjustment of morphology and geometric structure characteristics, which cannot fully meet the design requirements of efficient and stable photocatalysts. The photocatalytic performance and stability can be improved by surface design to construct abundant active sites and adjust the electronic structure. Research on the reaction mechanism of photocatalysis can help us understand the demand for photocatalytic structure characteristics in different reactions, thereby guiding the design of photocatalysts. In this paper, the advances in surface design and electronic structure regulation strategies of two-dimensional photocatalytic materials are reviewed from three aspects: light absorption; charge separation; and active sites, including element doping, heterojunction design, defect construction, single atom modification, and plasmonic metal loading. The effects on the reaction mechanism for typical air pollutant purification by regulating the electronic structure of two-dimensional photocatalytic materials are summarized. Finally, the problems and challenges associated with the development of two-dimensional photocatalytic materials are analyzed and discussed.
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Abdul Jabbar Khan Muhammad Sajjad Shaukat Khan Muhammad Khan Abdul Mateen Syed Shaheen Shah Numan Arshid Liang He Zeyu Ma Ling Gao Guowei Zhao 《Chemical record (New York, N.Y.)》2024,24(1):e202300302
As supercapacitor (SC) technology continues to evolve, there is a growing need for electrode materials with high energy/power densities and cycling stability. However, research and development of electrode materials with such characteristics is essential for commercialization the SC. To meet this demand, the development of superior electrode materials has become an increasingly critical step. The electrochemical performance of SCs is greatly influenced by various factors such as the reaction mechanism, crystal structure, and kinetics of electron/ion transfer in the electrodes, which have been challenging to address using previously investigated electrode materials like carbon and metal oxides/sulfides. Recently, tellurium and telluride-based materials have garnered increasing interest in energy storage technology owing to their high electronic conductivity, favorable crystal structure, and excellent volumetric capacity. This review provides a comprehensive understanding of the fundamental properties and energy storage performance of tellurium- and Te-based materials by introducing their physicochemical properties. First, we elaborate on the significance of tellurides. Next, the charge storage mechanism of functional telluride materials and important synthesis strategies are summarized. Then, research advancements in metal and carbon-based telluride materials, as well as the effectiveness of tellurides for SCs, were analyzed by emphasizing their essential properties and extensive advantages. Finally, the remaining challenges and prospects for improving the telluride-based supercapacitive performance are outlined. 相似文献
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可以预见,在相当一段时期内,能源和环境将是全球发展的两大主题. 其实,人类对能源的获取方式将对地球的生态环境和人类未来的生存状态和生活方式产生重要影响. 正因为如此,世界各国正在大力发展可再生能源和清洁能源. 电化学能源是将化学能高效转变为电能的一种能量转换方式,它历史悠久,但不断被改进和创新,尤其是近年来得到了较快的发展. 目前,电化学能源转换和存储器件主要包括一次电池(如锌锰电池等)、二次电池(如铅酸电池、镍氢电池、锂离子电池等)、燃料电池、金属-空气电池以及超级电容器等. 电化学能源和其它可再生能源相互补充、交叉利用将是未来清洁能源的主要发展方向. 相似文献