纳微尺度流体传质与反应特性探索

多相反应体系颗粒的运动及其相界面上的理化特性对于分子扩散、能量传输和反应转化起着决定性作用,它直接决定着整个化学转化过程的能耗、物耗甚至过程安全.本文简要介绍过去20年来南京大学团队及同行们在多相反应体系纳微流体及其界面性质与反应强化方面开展的一些探索工作,包括纳微流体界面传质与反应增强效应;单个纳微气泡的结构、运动、传质和反应特性;动态、非线性和非平衡特征;纳微流体颗粒的测试与表征;纳微气–液(水溶液)体系的羟基自由基检测及其新化学效应;以及纳微流体在反应强化方面的应用等.研究表明,纳微流体具有明显区别于宏观流体的理化特性,是一个极具挑战性的新兴领域,亟需进行深入研究和开发.在理论方面,需要在考虑动态、非平衡和尺度效应的基础上对经典的物理化学和平衡热力学的相关理论进行修正与拓展;在实验方面,需要设计和建立适用于纳微流体、动态、原位和多因子测试的仪器和表征系统;在应用方面,需要发明可大规模制备(10^(3)~10^(6)m^(3)h^(-1))和调控纳微颗粒尺度、特别是在大气液比(如5:1~100:1)情况下的纳微界面发生装置,同时开发面向千差万别应用场景的纳微流体反应器平台及操控系统.

基于聚合物凝胶和纸基的超分子光学传感阵列研究进展

超分子光学传感器阵列是分析化学中分子识别信息可视化的有效工具之一,这种传感器的优点是它们可以利用阵列系统来检测多种分析物.然而,大多数的光学传感器阵列主要在溶液状态下进行检测,大大限制了其应用的范围.发展固态光学传感器阵列,如聚合物凝胶和纸张,可以扩大光学传感器作为现场可视化分析工具的应用范围.本综述结合强大的数据处理技术和实际应用的便携式数字化检测技术,总结了固态介质参与的分子光学传感器阵列的应用与展望.

前言:手性发光材料专刊

手性是自然界的基本属性之一,描述的是一种物质与其镜像之间无法通过旋转、平移等操作而重合的结构特性,就像我们的左手与互成镜像的右手不重合.在生物学中,生物分子如蛋白质、DNA和糖类等都具有手性.手性特征决定了它们的生物活性、相互作用和功能.手性于药物分子的重要性已被广泛接受,而不对称合成的研究长期以来都是化学工作者的一个重要方向.除此之外,手性技术在农业化学品、食品添加剂、材料和器件等领域也有很大的应用前景.手性研究有望为医药、生物、信息和材料领域提供核心技术支持.

前言:纳微界面反应机理探索专刊

化学制造是我国国民经济的重要支柱,是现代炼油、石化、能源、新材料、生化制药、军工火药、轻工纺织、环境治理等产业的灵魂.气–液、液–液和气–液–固等多相化学反应则是化学制造的核心单元.多相反应过程所涉及的质量传递、能量传输和化学转化效率的高低,直接影响到产品质量、能耗物耗、生产安全和“三废”排放.

前言:分子机器专刊

“分子机器”是由多个分子尺度的单元通过机械互锁构成的动态功能分子,其动态可控特性可调控各级尺度下物质功能并创造新物质.2016年诺贝尔化学奖授予了让-皮埃尔·索维奇(Jean-Pierre Sauvage)、J.弗雷泽·斯托达特(Sir J.Fraser Stoddart)和伯纳德·L·费林加(Bernard L.Feringa)三位科学家,以表彰其设计并建造了最小的机器——“分子机器”.

利用水解反应可控构筑具有复杂拓扑结构的超分子组装体

分子经过水解反应往往会产生新的官能团,从而极大地改变其极性,并触发新的自组装行为.因此可以通过控制水解速率从热力学和动力学两个方面调节分子的自组装路径,最终构筑出复杂组装体[1].在自然界中,许多生物分子可以通过水解反应实现耗散的非平衡态自组装,从而获得结构复杂和功能可调节的组装体[2].

“生物质转化与轻工制造”基础研究发展战略思考——从科学基金资助布局到未来发展趋势

国家自然科学基金委员会于2021年启用了新的申请代码体系.本文通过梳理“生物质转化与轻工制造”(B0811)2021~2022年的申请和资助情况,从原料、转化路径到产品几个维度,总结了生物质化工基础研究的现状和存在问题,并对该方向未来的发展和布局提出了建议.

Roadmap for rechargeable batteries:present and beyond

Rechargeable batteries currently hold the largest share of the electrochemical energy storage market,and they play a major role in the sustainable energy transition and industrial decarbonization to respond to global climate change.Due to the increased popularity of consumer electronics and electric vehicles,lithium-ion batteries have quickly become the most successful rechargeable batteries in the past three decades,yet growing demands in diversified application scenarios call for new types of rechargeable batteries.Tremendous efforts are made to developing the next-generation post-Li-ion rechargeable batteries,which include,but are not limited to solid-state batteries,lithium–sulfur batteries,sodium-/potassium-ion batteries,organic batteries,magnesium-/zinc-ion batteries,aqueous batteries and flow batteries.Despite the great achievements,challenges persist in precise understandings about the electrochemical reaction and charge transfer process,and optimal design of key materials and interfaces in a battery.This roadmap tends to provide an overview about the current research progress,key challenges and future prospects of various types of rechargeable batteries.New computational methods for materials development,and characterization techniques will also be discussed as they play an important role in battery research.

A review of solid-state lithium metal batteries through in-situ solidification

High-energy-density lithium metal batteries are the next-generation battery systems of choice,and replacing the flammable liquid electrolyte with a polymer solid-state electrolyte is a prominent conduct towards realizing the goal of high-safety and high-specific-energy devices.Unfortunately,the inherent intractable problems of poor solid-solid contacts between the electrode/electrolyte and the growth of Li dendrites hinder their practical applications.The in-situ solidification has demonstrated a variety of advantages in the application of polymer electrolytes and artificial interphase,including the design of integrated polymer electrolytes and asymmetric polymer electrolytes to enhance the compatibility of solid–solid contact and compatibility between various electrolytes,and the construction of artificial interphase between the Li anode and cathode to suppress the formation of Li dendrites and to enhance the high-voltage stability of polymer electrolytes.This review firstly elaborates the history of in-situ solidification for solid-state batteries,and then focuses on the synthetic methods of solidified electrolytes.Furthermore,the recent progress of in-situ solidification technology from both the design of polymer electrolytes and the construction of artificial interphase is summarized,and the importance of in-situ solidification technology in enhancing safety is emphasized.Finally,prospects,emerging challenges,and practical applications of in-situ solidification are envisioned.

甲烷选择氧化单原子催化剂的研究进展

单原子催化剂在原子利用率卓越、配位环境具有可调谐性等方面表现出独特优势.其独特的原子结构通过诱导甲烷中C–H键的静电极化显著降低活化能.稳定中间体并防止反应产物的过度氧化,加速了甲烷在温和条件下的反应速率.本文综述了近年来单原子催化剂在甲烷低温液相条件下直接选择性氧化为C1~C2含氧化合物方面的研究进展.具体讨论了不同载体(碳基材料、分子筛、金属氧化物、金属有机框架)上呈原子级分散型活性位点催化剂的设计及制备方法、活化甲烷的反应机理和载体与催化性能之间的构效关系.最后,简单讨论了各类原子级分散型催化剂在甲烷选择氧化反应中的优势与挑战,并对单原子催化剂的发展进行了展望.

Solid-state lithium-ion batteries for grid energy storage:opportunities and challenges

The energy crisis and environmental pollution drive more attention to the development and utilization of renewable energy.Considering the capricious nature of renewable energy resource,it has difficulty supplying electricity directly to consumers stably and efficiently,which calls for energy storage systems to collect energy and release electricity at peak periods.Due to their flexible power and energy,quick response,and high energy conversion efficiency,lithium-ion batteries stand out among multiple energy storage technologies and are rapidly deployed in the grid.Pursuing superior performance and ensuring the safety of energy storage systems,intrinsically safe solid-state electrolytes are expected as an ideal alternative to liquid electrolytes.In this review,we systematically evaluate the priorities and issues of traditional lithium-ion batteries in grid energy storage.Beyond lithium-ion batteries containing liquid electrolytes,solid-state lithium-ion batteries have the potential to play a more significant role in grid energy storage.The challenges of developing solid-state lithium-ion batteries,such as low ionic conductivity of the electrolyte,unstable electrode/electrolyte interface,and complicated fabrication process,are discussed in detail.Additionally,the safety of solid-state lithium-ion batteries is re-examined.Following the obtained insights,inspiring prospects for solid-state lithium-ion batteries in grid energy storage are depicted.

纳微尺度溶液体系的精确计算

在纳微尺度上,分子性质、传质过程、化学反应等均与在宏观尺度表现不同.因此,近年来在生命科学、材料科学等领域对于纳微尺度下的液滴和溶液体系的研究蓬勃发展.采用计算模拟手段对相关体系的准确表征有助于揭示其在微观层面的分子机制,并为解开生命的奥秘、促进新材料的研发提供新的见解.本综述回顾了使用模拟方法,包括分子力场、量子化学方法以及结合机器学习等,研究此类体系的最新进展,重点关注纳微尺度下气液界面(包括空气/水、空气/溶液,以及大气/水)的溶液体系.此外,我们还对适用于纳微尺度溶液化学的计算模拟手段未来的发展进行了展望.

微/纳米反应器及纳微界面催化反应机理

学习自然是科学创造和科学生产的最佳驱动力.微/纳米反应器作为介观尺度下人工细胞仿生微纳结构材料代表,其微观形貌具有界限明显的中空腔室、丰富的纳米孔道等结构特征,在多相催化、能源存储和生物医药等领域具有重要的潜在应用价值.本文系统总结了微/纳米反应器定制策略开发、活性位精准锚定、纳米反应器效应探究及应用等方面的进展,重点集中在本课题组的代表性成果,以期为新型功能微纳米材料研制、介观尺度空间/界面反应过程及纳微界面理论探索提供良好的借鉴.

Layered oxide cathodes for sodium-ion batteries:microstructure design,local chemistry and structural unit

Because of the low price and abundant reserves of sodium compared with lithium,the research of sodium-ion batteries(SIBs)in the field of large-scale energy storage has returned to the research spotlight.Layered oxides distinguish themselves from the mains cathode materials of SIBs owing to their advantages such as high specific capacity,simple synthesis route,and environmental benignity.However,the commercial development of the layered oxides is limited by sluggish kinetics,complex phase transition and poor air stability.Based on the research ideas from macro-to micro-scale,this review systematically summarizes the current optimization strategies of sodium-ion layered oxide cathodes(SLOC)from different dimensions:microstructure design,local chemistry regulation and structural unit construction.In the dimension of microstructure design,the various structures such as the microspheres,nanoplates,nanowires and exposed active facets are prepared to improve the slow kinetics and electrochemical performance.Besides,from the view of local chemistry regulation by chemical element substitution,the intrinsic electron/ion properties of SLOC have been enhanced to strengthen the structural stability.Furthermore,the optimization idea of endeavors to regulate the physical and chemical properties of cathode materials essentially is put forward from the dimension of structural unit construction.The opinions and strategies proposed in this review will provide some inspirations for the design of new SLOC in the future.

氮掺杂中空碳负载的高熵合金在电化学去除铀方面的性能及机理探究

本文通过离子交换法制备了氮掺杂中空碳负载的高熵合金(HEA@HNPC),并用作电催化剂应用于水溶液中铀的去除.制备的HEA@HNPC具有灵活多变的元素组成、易于调控的表面电子结构和丰富的催化活性位点.分别探究了HEA@HNPC在纯水和模拟地下水中对铀的去除性能.结果表明,HEA@HNPC电催化剂对铀的去除表现出快速的动力学、较大的萃取容量、优异的选择性及增强的循环使用性能,放大实验发现HEA@HNPC对模拟地下水中铀的去除效率高达381.6 mg g^(-1)d^(-1).采用SEM、XRD和XPS对电化学产物分析发现,还原的U(Ⅳ)会与产生的CaCO_(3)沉淀形成混合物以固体的形式析出,实现铀的高效连续去除.电化学循环伏安曲线(CV)发现HEA@HNPC表面产生的具有强还原性的H_(ad)^(*)物种是实现U(Ⅵ)→U(Ⅳ)电还原的关键.这一发现为应用电化学技术去除水溶液中铀的机理研究提供了有意义的参考.

“In-N-out” design enabling high-content triethyl phosphate-based non-flammable and high-conductivity electrolytes for lithium-ion batteries

Safety issues related to flammable electrolytes in lithium-ion batteries(LIBs) remain a major challenge for their extended applications.The use of non-flammable phosphate-based electrolytes has proved the validity in inhibiting the combustion of LIBs.However,the strong interaction between Li^(+) and phosphate leads to a dominant solid electrolyte interphase(SEI) with limited electronic shielding,resulting in the poor Li^(+) intercalation at the graphite(Gr) anode when using high-phosphate-content electrolytes.To mitigate this issue and improve Li^(+) insertion,we propose an “In-N-Out” strategy to render phosphates “noncoordinative”.By employing a combination of strongly polar solvents for a “block effect” and weakly polar solvents for a “drag effect”,we reduce the Li^(+)–phosphate interaction.As a result,phosphates remain in the electrolyte phase(“In”),minimizing their impact on the incompatibility with the Gr electrode(“Out”).We have developed a non-flammable electrolyte with high triethyl phosphate(TEP) content(>60 wt.%),demonstrating the excellent ion conductivity(5.94 mS cm^(-1) at 30 ℃) and reversible Li^(+) intercalation at a standard concentration(~1 mol L^(-1)).This approach enables the manipulation of multiple electrolyte functions and holds the promise for the development of safe electrochemical energy storage systems using non-flammable electrolytes.

Perspective of alkaline zinc-based flow batteries

Energy storage technologies have been identified as the key in constructing new electric power systems and achieving carbon neutrality,as they can absorb and smooth the renewables-generated electricity.Alkaline zinc-based flow batteries are well suitable for stationary energy storage applications,since they feature the advantages of high safety,high cell voltage and low cost.Currently,many alkaline zinc-based flow batteries have been proposed and developed,e.g.,the alkaline zinc–iron flow battery and alkaline zinc–nickel flow battery.Their development and application are closely related to advanced materials and battery configurations.In this perspective,we will first provide a brief introduction and discussion of alkaline zinc-based flow batteries.Then we focus on these batteries from the perspective of their current status,challenges and prospects.The bottlenecks for these batteries are briefly analyzed.Combined with the practical requirements and development trends of alkaline zinc-based flow battery technologies,their future development and research direction will be summarized.

辽东湾海水中金属基纳米颗粒的赋存水平与环境风险

纳米科技的迅速发展使得纳米材料,特别是金属基纳米颗粒(NPs)的环境污染问题备受关注.海洋(特别是近海海湾)是金属基NPs重要的“汇”,然而环境浓度的缺失阻碍了金属基NPs在海洋环境中的风险评估.本文采用单粒子电感耦合等离子体质谱法(sp-ICP-MS)探究了辽东湾海水中Ag、Ti、Cu和Zn基NPs的赋存水平及空间分布,并基于金属基NPs对海洋生物的预测无效应浓度(PNECs),使用风险表征比(RCR)对4种金属基NPs在辽东湾的环境风险进行了评估.结果表明,使用sp-ICP-MS以稀释法(Ti、Cu和Zn基NPs)和浊点萃取法(Ag基NPs)可以实现对4种金属基NPs的准确定量,回收率分别为97.1%、96.4%、95.3%和96.7%.空间分布表明,辽东湾中Ti基NPs的平均浓度最高(3.98×10^(8)个/L),其次为Ag、Cu和Zn基NPs;Ag基NPs在辽东湾西部沿岸浓度最高(6.81×10^(7)个/L),其他3种NPs则在北部沿岸大凌河口浓度最高,分别为1.87×10^(9)(Ti基NPs)、5.86×10^(7)(Ag基NPs)和2.12×10^(7)个/L(Zn基NPs).4种金属基NPs中,Ag基NPs的环境风险最高,在所有调查的16个站位中,有15个站位为“中风险”;4种NPs的总体环境风险(RCRtotal)在所有调查站位均处于“中风险”,且Ag基NPs对总体环境风险的贡献最大(>50%).本研究将有助于科学认识辽东湾海域金属基NPs的赋存水平和客观评估其环境风险.

苯并噻吩稠合双硼荧光染料的手性光学性质及组装手性放大研究

近年来,基于有机硼的手性发光材料因具有其独特结构和性质备受关注.本研究在吡咯吡啶腙肼双硼荧光团(BOPPY)上同时引入了苯并噻吩和手性胺侧链,成功构建了一种新型苯并噻吩稠环手性BOPPY.相对于手性母体,苯并噻吩稠环的导入实现了其圆二色(CD)和圆偏振发光(CPL)光谱分别红移50和70 nm,同时伴随手性旋向的反转.此外,手性BOPPY分子在有机溶剂中展现出镜像的CD、明亮的黄绿色CPL(Φ_(F)=0.37,540 nm,g_(lum)=1×10^(-4))、高摩尔吸光系数、大斯托克斯位移、良好的热稳定性,以及荧光量子产率高达25%的强薄膜固态发射(538 nm,g_(lum)=7.4×10^(-4)).更有趣的是,手性BOPPY分子在水中表现出聚集诱导荧光增强活性,其在表面活性剂作用下进行共组装的超分子体系显示出手性放大行为,得到的聚集体表现出显著增强的圆偏振发光性质(566 nm,g_(lum)=0.069),组装体g_(lum)相比于其分子态提升了690倍.推测手性放大机制可能是手性BOPPY分子和表面活性剂在弱相互作用协同驱动进行各向异性调节,从而构建了有序的手性纳米结构.

气候变化与海洋微塑料污染的相互影响研究进展

气候变化和海洋微塑料污染已成为全球关注的热点问题,两者在相当长的一段时间内会同时存在.然而,基于文献报道的实验结果和环境监测数据,关于气候变化和海洋微塑料污染的研究大多是相互独立的,缺乏对两者相互影响的清晰认知.本文通过综述全球气候变化状况和海洋微塑料的污染现状,总结了气候变化下海洋生态环境的改变,特别是海水升温、酸化、低氧等与海洋微塑料污染之间的相互影响,发现气候变化会加剧海洋微塑料污染,改变微塑料的海洋环境行为,同时海洋微塑料污染也会影响气候变化,加剧气候变暖、海洋酸化和低氧,所以两者是密切相关的.本文还展望了未来的研究方向和前景,以期为有效应对全球气候变化和海洋微塑料污染提供重要的理论基础.