“蛋黄蛋壳”结构纳米电极材料设计及在锂/钠离子/锂硫电池中的应用

“蛋黄蛋壳”结构纳米材料,具有易于调控的“蛋黄”、“蛋壳”和“空腔”结构,可视作“纳米反应器”,在催化、储能等领域表现出显著的应用潜力。尤其在电化学能源存储和转换方面,该结构纳米电极具有大的比表面积和独特的核壳结构,在充放电过程中可缓解电极的体积变化,提供快速的离子/电子输运通道,强化中间产物的吸附和提升转换反应效率等,能显著提高电极稳定性、倍率性能和循环性能,是一类较为理想的电极材料。本文针对“蛋黄蛋壳”结构纳米电极在锂/钠离子电池、锂硫电池等新兴二次电池领域的实际应用,总结了具有该结构纳米电极的设计与合成策略,包括:模板法、奥斯特瓦尔德熟化、电化学置换、克肯达尔效应等,评述了各种策略的优缺点以及电极材料的应用进展,最后对该类材料在锂/钠体系及锂硫电池二次电池方面的研究与应用前景进行了展望。     

Al-MOF基多级孔Al2O3固定化酶反应器的构筑及构效关系研究

针对生物酶在固相载体负载后存在的催化活性与稳定性之间“此消彼长”的问题, 本工作采用“自牺牲模板”策略以铝基金属有机骨架材料(Al-MOF)为前驱体设计制备多级孔Al₂O₃ (MHAl₂O₃)材料, 再以“聚多巴胺(PDA)”仿生膜对材料表面进行功能化修饰后用以固载辣根过氧化物酶(HRP). 通过调节前驱体的煅烧温度来实现载体孔径大小的调控, 探讨了载体的孔道限域效应对固定化酶反应器催化活性的影响, 所得固定化酶反应器的热稳定性和重复使用性显著提高. 为了解析固定化酶反应器的构效关系, 采用酶动力学和热动力学参数研究了固定化酶反应器催化过程中酶与底物的相互作用, 结果表明固载后酶分子对底物的亲和性和专一性得到提升. 将固定化酶反应器用于模拟废水中苯胺黑药的催化降解时, 表现出非常高效的催化效率.     

从固体化学到凝聚态化学

“凝聚态化学”是化学学科一个新的发展领域,其基本思想是超越分子和理想晶体的界限,多层次地研究物质的组成、结构、性质、制备以及它们之间的关系。本文简要回顾了从固体物理到凝聚态物理的历史以及固体化学的发展历史,分析了固体化学的学科特点,指出固体化学的发展必然孕育着“凝聚态化学”的形成,同时指出,化学学科中的多个领域也都会将“凝聚态化学”作为自己的发展方向。建议了从固体化学向“凝聚态化学”发展的途径:完善固体化学学科的知识体系,拓展固体化学的知识范围,创造“凝聚态化学”的标志性成果。最后强调,与凝聚态物理学家密切合作,共建“凝聚态科学”大厦。     

凝聚态化学的研究对象与主要科学问题

本文提出了“凝聚态化学(Condensed Matter Chemistry)”的概念,提出其研究对象是由传统化学上被视为反应主体的原子、离子以及分子等“基本粒子”,藉“稳定的粘连关系”凝聚形成的具有特定组成、多层次结构与性质、功能的物质凝聚态。本文以固态为例,讨论了(1)凝聚态的多层次结构;(2)凝聚态的化学性质与化学反应;(3)凝聚态构筑化学中的前沿科学问题;(4)凝聚态化学中的高新表征方法与技术的发展与开拓。并对四个领域中的主要科学问题进行了比较深入的探讨,为进一步再认识传统化学,特别是对其中心问题,即化学反应的再认识提供了方向与基础,为开展“凝聚态的多层次结构-化学性质与化学反应-凝聚态物质的构筑定向合成与精准制备”三个方面的关系研究,总结规律与“分态”建立“凝聚态结构理论”与“凝聚态化学反应理论”,建设“凝聚态化学”提供了科学体系与内容,并为进一步开展“凝聚态工程学”研究提供了前提与基础。     

大气“霾化学”:概念提出和研究展望

大气污染是人类面临的重大环境挑战。我国大气污染具有高度的复合污染特征,其形成过程既有高强度的颗粒物均相成核现象,又有多介质非均相致霾过程,同时耦合了强的大气氧化性以及O₃污染,是不同于洛杉矶光化学烟雾和伦敦烟雾的新型“霾化学”烟雾污染。“霾化学”区别于并突破现有的理论认识,是解析我国典型多介质复合污染环境下PM_2.5成因以及PM_2.5与O₃污染间非线性复杂关系,综合研究气、液、固多介质非均相过程的大气污染化学。研究“霾化学”过程对精准控制我国乃至其他国家大气复合污染意义重大。本文提出和总结了大气“霾化学”概念,并对“霾化学”理论的完善和发展进行了展望。     

用于分离油水乳液的先进材料

海洋原油泄漏事故的频发以及工业污水排放量的日益增加,给生态环境和人类健康造成了巨大的威胁,因此,开发应用于油水分离的先进材料是重要的研究任务。相较于不混溶的油水混合物,油水乳液(也称为乳化油水)的分离是一个更加艰巨的挑战。本文以分离油水乳液的材料作为研究体系,首先从本质上分析了油水乳液的形成机理以及分离原理,强调了“尺寸筛分”效应和膜破乳技术的重要性;然后从基材的角度全面介绍并讨论了常用于分离乳化油水的先进材料的最新进展,详细阐述了各种不同改性方法在油水分离领域中的应用。对材料进行改性的出发点是“合适的孔径”以及“特殊润湿性能”,并能满足优异的分离能力、渗透能力、抗污染能力、机械能力和稳定性,而这些性能在实际的分离操作中是非常关键的。环境系统在未来会变得越来越复杂,真实环境下的油水乳液大多含有较多的污染物,而且分离条件大多较苛刻,因此油水分离材料需要不断地改进,以满足这样的条件。我们相信,未来能在苛刻条件下高效分离多种油水乳液和其他杂质的多功能性先进材料会有巨大的应用前景。     

锂硫电池中的催化作用

锂硫电池理论能量密度高达2600 Wh·kg^-1,单质硫的理论容量可达1675 mAh·g^-1,远高于商业化的锂离子电池正极材料,但多硫化锂的“穿梭效应”等问题对其性能影响严重。目前研究主要采用基于“阻挡”的物理限制和化学吸附策略将多硫化锂限制在正极侧。而基于“疏导”的催化转化策略则通过加快氧化还原反应动力学,在抑制“穿梭效应”的同时实现降低过电位、诱导Li₂S均匀沉积等功能。本文综述了锂硫电池中的催化作用,基于是否产生氧化还原中间体将其分为吸附-转化机制和氧化还原介导机制两类;并介绍了相关的材料及常用的表征技术和研究方法。     

烯烃的氢甲酰化串联反应研究

氢甲酰化串联反应是在氢甲酰化反应的基础上,与一个或多个不同类型的反应“一锅法”实现醛类化合物的后续定向转化,得到新的有机分子的合成方法。该反应的产物在日化工业、农业、医药中间体的生产中具有十分重要的用途。本文首先简述了近年来烯烃氢甲酰化串联反应制备高附加值化学品的重要性,随后重点介绍了几种常见的烯烃氢甲酰化串联反应:“异构化-氢甲酰化”串联反应、“氢甲酰化-缩醛化”串联反应、“氢甲酰化-氢化”串联反应和“氢甲酰化-(还原)胺化”串联反应等,以及其在设计新型(多功能)催化剂体系和高效合成目标产物方面的研究进展,最后总结了烯烃氢甲酰化串联反应存在的问题以及对未来发展趋势进行了展望。     

基于单体设计的可回收高分子研究进展

现代社会的发展越来越依赖高分子材料, 但其大量使用后不当处置不仅造成资源浪费, 更造成严重的生态环境问题. 将废弃高分子材料解聚回单体, 然后通过聚合反应重新生成与解聚之前等值的高分子材料, 实现高分子材料循环利用被认为是解决上述问题的重要手段之一. 近年来, 通过单体设计发展“理想单体”从而调节“聚合—解聚”平衡, 实现温和条件下高分子材料闭环回收的策略取得了长足进展. 本文将从闭环回收聚酯、聚碳酸酯、含硫聚合物、聚环状烯烃等方面进行综述, 并对该领域的挑战和未来发展方向进行简要讨论.     

手性氨基酸酰胺催化剂的发现及研究进展

自从L-脯胺酰胺被发现能高效催化不对称aldol反应以来,手性氨基酸酰胺催化剂的设计及不对称催化研究一直受到关注。特别是“烯胺-双氢键”模型的提出为设计新型有机小分子催化剂提供了理论依据,使催化剂的结构设计趋于多样化。本文重点总结了含有单氢键给体、双氢键给体及多氢键给体的氨基酸酰胺催化的不对称催化反应,主要包括不对称直接aldol反应、Mannich反应、Michael加成反应、环加成反应、串联环化反应、Biginelli反应等方面的研究进展。     

Design Strategies for High-Performance Aqueous Zn/Organic Batteries

Organic electroactive compounds are attractive to serve as the cathode materials of aqueous zinc-ion batteries (ZIBs) because of their resource renewability, environmentally friendliness and structural diversity. Up to now, various organic electrode materials have been developed and different redox mechanisms are observed in aqueous Zn/organic battery systems. In this Minireview, we present the recent developments in the energy storage mechanisms and design of the organic electrode materials of aqueous ZIBs, including carbonyl compounds, imine compounds, conductive polymers, nitronyl nitroxides, organosulfur polymers and triphenylamine derivatives. Furthermore, we highlight the design strategies to improve their electrochemical performance in the aspects of specific capacity, output voltage, cycle life and rate capability. Finally, we discuss the challenges and future perspectives of aqueous Zn/organic batteries.     

有机电极材料过渡态的研究进展

有机电极材料具有理论比容量大、结构可设计性强、加工使用过程环境友好等优点被广泛应用于二次电池的研究中。有机电极材料在氧化还原过程会产生具有不成对电子的自由基中间体,自由基中间体的稳定程度影响电极材料的电化学性能。通过改变材料的结构可以调控自由基中间体的稳定性,从而优化有机电极材料的电化学性能。本文对有机电极材料在电化学过程中产生的自由基中间体进行了分类介绍,阐明了材料结构、自由基中间体稳定性和电化学性能之间的关系。     

Material Design Concept of Lithium‐Excess Electrode Materials with Rocksalt‐Related Structures for Rechargeable Non‐Aqueous Batteries

Dependence on lithium‐ion batteries for automobile applications is rapidly increasing, and further improvement, especially for positive electrode materials, is indispensable to increase energy density of lithium‐ion batteries. In the past several years, many new lithium‐excess high‐capacity electrode materials with rocksalt‐related structures have been reported. These materials deliver high reversible capacity with cationic/anionic redox and percolative lithium migration in the oxide/oxyfluoride framework structures, and recent research progresses on these electrode materials are reviewed. Material design strategies for these lithium‐excess electrode materials are also described. Future possibility of high‐energy non‐aqueous batteries with advanced positive electrode materials is discussed for more details.     

Emerging Lithiated Organic Cathode Materials for Lithium-Ion Full Batteries

Organic electrode materials have application potential in lithium batteries owing to their high capacity, abundant resources, and structural designability. However, most reported organic cathodes are at oxidized states (namely unlithiated compounds) and thus need to couple with Li-rich anodes. In contrast, lithiated organic cathode materials could act as a Li reservoir and match with Li-free anodes such as graphite, showing great promise for practical full-battery applications. Here we summarize the synthesis, stability, and battery applications of lithiated organic cathode materials, including synthetic methods, stability against O₂ and H₂O in air, and strategies to improve comprehensive electrochemical performance. Future research should be focused on new redox chemistries and the construction of full batteries with lithiated organic cathodes and commercial anodes under practical conditions. This Minireview will encourage more efforts on lithiated organic cathode materials and finally promote their commercialization.     

Nanostructured strategies towards boosting organic lithium-ion batteries

Pursuing material development for next-generation batteries,organic electrode materials have shown great potential for lithium-ion batteries.However,their widespread adopting is plagued by intrinsic problems such as poor electronic conductivity,high dissolution inside electrolytes and unstable chemical peculiarity.Recently,nanostructured-strategies promoted organic electrodes with exotic properties for enhancing electron and ion transport together with the stability during electrochemical process,have received increasing attention and have been extensive applied in boosting the organic lithium-ion based energy storage.In this review,we summarize the applications of nanostructures to improve the performance of both organic anodes and cathodes,including(i)nanoscale design of zero-dimensional organic electrode materials,(ii)strategies of one-dimensional nanostructured organic electrode materials,(iii)construction of two-dimensional nanosized organic composite electrodes,and(iv)three-dimensional exploration of nanosized organic electrodes.We hope to stimulate high-quality applied research on understanding and handling the relationship between the nanostructure and performance of organic lithium-ion batteries that might speed up the commercialization of organic lithium ion batteries.     

可充锂电池醌类化合物电极材料

醌类化合物电极材料具有理论比容量高、结构可设计、成本低廉和绿色可持续等优点,被认为是可充锂电池理想的电极材料。本文介绍了醌类化合物电极材料的分类及其结构特点、电化学工作原理及其电化学性能,对醌类化合物的发展、面临的问题等方面进行了概括,探讨了提高该类电极材料电化学性能的方法,并对醌类化合物电极材料的发展方向进行了展望。     

In Situ Enzyme Immobilization by Covalent Organic Frameworks

Enzyme immobilization is a widely reported method to favor the applicability of enzymes by enhancing their stability and re-usability. Among the various existing solid supports and immobilization strategies, the in situ encapsulation of enzymes within crystalline porous matrices is a powerful tool to design biohybrids with a stable and protected catalytic activity. However, to date, only a few metal–organic frameworks (MOFs) and hydrogen-bonded organic frameworks (HOFs) have been reported. Excitingly, for the first time, Y. Chen and co-workers expanded the in situ bio-encapsulation to a new class of crystalline porous materials, namely covalent organic frameworks (COFs). The enzyme@COF materials not only exhibited high enzyme loading with minimal leaching, high catalytic activity and selectivity, chemical and long-term stability and recyclability but could also be scaled up to a few grams. Undoubtedly, this work opens new striking opportunities for enzymatic immobilization and will stimulate new research on COF-based matrices.     

基于层状双金属氢氧化物的电化学生物传感器研究进展

层状双金属氢氧化物（LDHs）具有开放的二维平面结构和良好的生物相容性,是非常适合于将生物酶固定在电极表面用于生物传感器的主体材料。本文介绍了酶在LDHs材料上的固定方法,综述了近年来基于这类二维层状材料的各种电化学生物传感器的研究进展,讨论了不同类型生物传感器的设计原理和电子传递机理,并对LDHs在电化学生物传感领域...     

关于水系锌离子电池中无氧钒基正极材料的综述

水系锌离子电池具有功率密度高、环境友好、安全性高、低成本和锌资源丰富等优点，被认为具有潜力成为下一代电化学储能系统。然而，正极材料较差的电化学性能制约了水系锌离子电池的未来发展。尽管氧化锰、氧化钒、普鲁士蓝类似物、有机材料等多种材料已被广泛研究，设计具有高性能的理想正极材料仍面临着巨大挑战。无氧钒基化合物由于具有高的电导率、大的层间距、低的离子扩散势垒和高的理论比容量，受到越来越多的关注。本文总结了无氧钒基化合物的研究进展，包括电极材料的设计、改善其电化学性能的有效途径以及复杂的储能机制，提出了无氧钒基化合物目前面临的挑战和未来的发展前景，为进一步制备新型高性能钒基正极材料提供指导。     

Molecular Tailoring of p–type Organics for Zinc Batteries with High Energy Density

P-type organic electrode materials are known for their high redox voltages and fast kinetics. However, single-electron p-type organic materials generally exhibit low capacity despite high operating voltage and stability, while some multi-electron p-type organic materials have high theoretical capacity but low stability. To address this challenge, we explore the possibility of combining single-electron and multi-electron units to create high-capacity and stable p-type organic electrodes. We demonstrate the design of a new molecule, 4,4′-(10H-phenothiazine-3,7-diyl) bis (N,N-diphenylaniline) (PTZAN), which is created by coupling the triphenylamine molecule and the phenothiazine molecule. The resulting PTZAN||Zn battery shows excellent stability (2000 cycles), high voltage (1.3 V), high capacity (145 mAh g⁻¹), and energy density of 187.2 Wh kg⁻¹. Theoretical calculations and in/ex situ analysis reveal that the charge storage of the PTZAN electrode is mainly driven by the redox of phenothiazine heterocycles and triphenylamine unit, accompanied by the combination/release of anions and Zn²⁺.