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电催化水分解产氢作为一种有前途的制氢技术被全世界研究者广泛关注.然而,此领域仍然缺少一种高效、无污染的催化剂,以降低能耗,提升反应动力学,进而推进电解水的实际应用.近年来研究发现,具有短程有序、长程无序特征的非晶纳米材料在电解水领域表现出极其优异的性能.有趣的是,固有的无序结构赋予了非晶纳米材料丰富的高活性位点.鉴于此,本文综述了非晶纳米材料的制备策略以及表征方法,并且对其高活性来源进行了系统地分析.此外,本文通过分析近几十年的研究成果指出了非晶纳米材料在电解水领域面临的挑战和应用前景.非晶纳米材料的合成方法主要分为两类:直接合成和间接合成.直接合成主要包括:电沉积、光化学金属-有机沉积、气溶胶-喷雾辅助法、反胶束溶胶-凝胶法、水热法、共沉淀法和氧化还原法.其中,气溶胶-喷雾辅助技术可以通过控制母液中金属离子的浓度精准地控制非晶纳米材料中各种金属元素的组成,从而有目的地调控并优化催化活性.间接合成主要分为原位转化和非原位转化.原位转化是指晶体材料在反应过程中表面会原位转化为非晶结构作为反应的真实活性物质.非原位转化是指当纳米材料尺度非常小时,高表面能将会破坏材料的结晶度得到非晶材料.另外,非晶材料长程无序的特点给其表征带来极大挑战.目前,对于非晶材料表征的一般流程是:首先通过X射线粉末衍射确定非晶结构,并通过透射电子显微镜以及扫描电子显微镜探索其形貌结构;再通过选区电子衍射以及高角度环形暗场扫描透射电子显微镜进一步确定非晶结构;然后,通过能谱、电感耦合等离子体发射光谱和X射线光电子能谱分析其化学组成及化学态;最后,采用拉曼光谱和同步辐射数据提供晶体结构信息.本文对非晶纳米材料高活性的起源进行了探究.在电解水领域,非晶纳米材料通常表现出优于晶体材料的性能.优异的活性与活性位点数量的增多以及活性位点活性的提升有关:(1)非晶纳米材料具有长程无序的特征,可以暴露更多活性位点,并且其表面存在的大量悬挂键也可以作为活性位点;(2)非晶纳米材料的活性位点可以拓展至催化剂体相内部,大幅提升了活性位点数量;(3)非晶纳米材料结构灵活性高,活性位点在催化反应过程中可以转变成任意形状,提升了活性位点的活性;(4)非晶纳米材料的高韧性和应变能力赋予其较高的稳定性.非晶纳米材料已广泛应用于电解水领域,但仍然存在一些问题:(1)非晶纳米材料由于原子级结构不确定,其电催化机理很难探究;(2)理论模拟作为研究电化学反应途径的有力工具很难应用于非晶纳米材料的研究;(3)随着无序程度的增加,活性位点数量和活性逐渐增加,但电导率逐渐下降.尽管如此,由于非晶纳米材料结构灵活性高和自重组能力快速,人们对其在电解水领域的研究兴趣越来越大,并且该领域显示出良好的应用前景,高效非晶纳米材料的设计合成及其催化机理的研究将成为今后研究的重点. 相似文献
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无酶电化学生物传感器具有环境适用性强、稳定性高、材料简单易得、灵敏度高、检测限低等特点,近年来受到研究者广泛关注。纳米材料有类酶活性,表现出类似天然酶的酶促反应动力学和催化机理,且能够增强界面吸附性能,增加电催化活性,并促进电子转移动力学,从而广泛应用于无酶电化学生物传感器。本文探索了具有电催化活性的纳米材料及其修饰电极的制备方法,介绍了无酶电化学传感器在医疗诊断、食品检测、环境检测以及其他领域中的应用,讨论了开发基于纳米材料的电化学传感器的未来机遇和挑战。 相似文献
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《催化学报》2021,(8)
电催化水分解产氢作为一种有前途的制氢技术被全世界研究者广泛关注.然而,此领域仍然缺少一种高效、无污染的催化剂,以降低能耗,提升反应动力学,进而推进电解水的实际应用.近年来研究发现,具有短程有序、长程无序特征的非晶纳米材料在电解水领域表现出极其优异的性能.有趣的是,固有的无序结构赋予了非晶纳米材料丰富的高活性位点.鉴于此,本文综述了非晶纳米材料的制备策略以及表征方法,并且对其高活性来源进行了系统地分析.此外,本文通过分析近几十年的研究成果指出了非晶纳米材料在电解水领域面临的挑战和应用前景.非晶纳米材料的合成方法主要分为两类:直接合成和间接合成.直接合成主要包括:电沉积、光化学金属-有机沉积、气溶胶-喷雾辅助法、反胶束溶胶-凝胶法、水热法、共沉淀法和氧化还原法.其中,气溶胶-喷雾辅助技术可以通过控制母液中金属离子的浓度精准地控制非晶纳米材料中各种金属元素的组成,从而有目的地调控并优化催化活性.间接合成主要分为原位转化和非原位转化.原位转化是指晶体材料在反应过程中表面会原位转化为非晶结构作为反应的真实活性物质.非原位转化是指当纳米材料尺度非常小时,高表面能将会破坏材料的结晶度得到非晶材料.另外,非晶材料长程无序的特点给其表征带来极大挑战.目前,对于非晶材料表征的一般流程是:首先通过X射线粉末衍射确定非晶结构,并通过透射电子显微镜以及扫描电子显微镜探索其形貌结构;再通过选区电子衍射以及高角度环形暗场扫描透射电子显微镜进一步确定非晶结构;然后,通过能谱、电感耦合等离子体发射光谱和X射线光电子能谱分析其化学组成及化学态;最后,采用拉曼光谱和同步辐射数据提供晶体结构信息.本文对非晶纳米材料高活性的起源进行了探究.在电解水领域,非晶纳米材料通常表现出优于晶体材料的性能.优异的活性与活性位点数量的增多以及活性位点活性的提升有关:(1)非晶纳米材料具有长程无序的特征,可以暴露更多活性位点,并且其表面存在的大量悬挂键也可以作为活性位点;(2)非晶纳米材料的活性位点可以拓展至催化剂体相内部,大幅提升了活性位点数量;(3)非晶纳米材料结构灵活性高,活性位点在催化反应过程中可以转变成任意形状,提升了活性位点的活性;(4)非晶纳米材料的高韧性和应变能力赋予其较高的稳定性.非晶纳米材料已广泛应用于电解水领域,但仍然存在一些问题:(1)非晶纳米材料由于原子级结构不确定,其电催化机理很难探究;(2)理论模拟作为研究电化学反应途径的有力工具很难应用于非晶纳米材料的研究;(3)随着无序程度的增加,活性位点数量和活性逐渐增加,但电导率逐渐下降.尽管如此,由于非晶纳米材料结构灵活性高和自重组能力快速,人们对其在电解水领域的研究兴趣越来越大,并且该领域显示出良好的应用前景,高效非晶纳米材料的设计合成及其催化机理的研究将成为今后研究的重点. 相似文献
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设计廉价高效的过渡金属/氮共掺杂碳材料并作为铂基材料的替代物应用于电催化氧还原反应(ORR),是目前加速燃料电池技术大规模商业化的有效途径之一,也是当前研究的焦点和难点.本文通过表面活性剂的辅助在氧化石墨烯(GO)表面原位生长钴掺杂的ZIF-8(Co-ZIF-8),以此为前驱体经过一步碳化得到二维5%Co/N-GO碳纳米材料,实现了钴/氮活性位点和介孔结构的同步构筑.5%Co/N-GO在碱性条件下具有非常优异的ORR催化性能,其起始电位、半波电位、极限电流密度和稳定性都优于商业Pt/C,同时表现出极优的四电子选择性.这些优异的性能主要得益于二维超薄的介孔结构大大促进了反应过程的物料传输和活性位点的暴露率;同时,高度分散的Co Nx活性位点与氮掺杂位点产生高效的协同催化作用,显著增强了该材料的电催化氧还原性能. 相似文献
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金属纳米材料在电催化应用中展示出良好的性能,但是它们依旧面临着稳定性差和调控策略有限的问题。引入第二组分是一种有效的策略,能够很好的改善其催化活性与稳定性。在这篇综述中,我们概述了结合金属纳米材料和瓜环(CB[n])用于电催化应用。瓜环是一系列的具有刚性结构、高稳定性、与金属配位的官能团的大环,它们适合稳定金属纳米材料并对其进行调控。本文讨论按照瓜环的功能分类,包含瓜环作为保护剂、瓜环基的超分子自组装体以及瓜环作为前驱体制备氮掺杂多孔碳。多种金属纳米催化剂,包括金属纳米颗粒(Pt,Ir,Pd,Ru,Au)、金属单原子(Fe,Co,Ni)以及过渡金属碳化物(TMCs)成功与瓜环或瓜环衍生的碳材料复合,这些复合材料在许多电催化反应中展示出优异的性能和稳定性,反应包括了氧还原反应(ORR)、析氧反应(OER)、析氢反应(HER)、二氧化碳还原反应(CO2RR)、甲烷氧化反应(MOR)、乙醇氧化反应(EOR)。其中,一些金属-瓜环复合物可进一步作为双功能催化剂用于全水解和燃料电池中。瓜环基的纳米催化剂具有媲美商用催化剂的性能,甚至其稳定性可优于商用催化剂。实验分析以及密度泛函理论(DFT)计算... 相似文献
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Ilija Najdovski Anthony P. O'Mullane Suresh K. Bhargava 《Electrochemistry communications》2010,12(11):1535-1538
The galvanic replacement reaction has received considerable interest due to the creation of novel bimetallic nanomaterials that minimise the use of expensive metals while maintaining enhanced electrocatalytic properties for certain reactions. In this work we investigate the galvanic replacement of electrochemically synthesised iron nanocubes on glassy carbon, with gold and palladium. The resultant nanomaterials demonstrate quite a difference in morphology; the original cuboid like template is maintained in the case of gold but destroyed when palladium is used. The electrochemical and electrocatalytic behaviours of these materials are reported for reactions such as methanol oxidation, hydrogen evolution and oxygen reduction. 相似文献
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纳米尺度的金由于常表现出有趣的尺寸效应和物理化学特性而被大量应用于催化反应中,但是其在电催化反应中的应用却十分有限. 本文以水为溶剂、HAuCl4为前驱体、十二烷基聚乙二醇醚(Brij 35)等为软模板剂、NaBH4为还原剂、活性炭或石墨烯为载体,在温和反应条件下获得担载型金纳米电催化剂. 本文考察并优化了关键制备参数和样品纯化方法,最终确定NaBH4的最佳浓度区间为5 ~ 10mmol•L-1,Brij 35的最佳浓度约为1 mmol•L-1,在3 ~ 16 oC下金纳米颗粒的尺寸容易控制,石墨烯和活性炭(EC600)是金纳米颗粒的良好载体. 在优化的反应条件下,金纳米颗粒的粒径可以被控制在1 ~ 4 nm. 热处理法可以有效去除表面活性剂,纯化后的担载型纳米金电催化剂在醇类小分子的氧化反应中表现出良好的性能. 相似文献
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Yikang Cong Shengsheng Huang Yan Mei Prof. Dr. Ting-Ting Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(64):15866-15888
Electrocatalytic water splitting has been considered as a promising strategy for the sustainable evolution of hydrogen energy and storage of intermittent electric energy. Efficient catalysts for electrocatalytic water splitting are urgently demanded to decrease the overpotentials and promote the sluggish reaction kinetics. Carbon-based composites, including heteroatom-doped carbon materials, metals/alloys@carbon composites, metal compounds@carbon composites, and atomically dispersed metal sites@carbon composites have been widely used as the catalysts due to their fascinating properties. However, these electrocatalysts are almost powdery form, and should be cast on the current collector by using the polymeric binder, which would result in the unsatisfied electrocatalytic performance. In comparison, a self-supported electrode architecture is highly attractive. Recently, self-supported metal–organic frameworks (MOFs) constructed by coordination of metal centers and organic ligands have been considered as suitable templates/precursors to construct free-standing carbon-based composites grown on conductive substrate. MOFs-derived carbon-based composites have various merits, such as the well-aligned array architecture and evenly distributed active sites, and easy functionalization with other species, which make them suitable alternatives to non-noble metal-included electrocatalysts. In this review, we intend to show the research progresses by employment of MOFs as precursors to prepare self-supported carbon-based composites. Focusing on these MOFs-derived carbon-based nanomaterials, the latest advances in their controllable synthesis, composition regulation, electrocatalytic performances in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting (OWS) are presented. Finally, the challenges and perspectives are showed for the further developments of MOFs-derived self-supported carbon-based nanomaterials in electrocatalytic reactions. 相似文献
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《中国科学:化学(英文版)》2021,(7)
With advances in cluster chemistry, atomically precise gold nanoclusters(NCs) with well-defined composition and tunable structure provide an exciting opportunity to uncover the specific roles of the geometrical and electronic structures as well as the capped ligands in overall catalytic performances. The Au NCs possess quantum energy levels and unique optical properties,which have exhibited unexpected photocatalytic and electrocatalytic activities. In this review, we first highlight the electrocatalytic applications of Au NCs, including hydrogen evolution reaction, oxygen reduction reaction, CO_2 reduction and catalytic oxidation reactions, and then present Au NCs-driven photocatalytic applications such as selective organic reactions, decomposition of pollutants and energy conversion reactions. Finally, we conclude this review with a brief perspective on the catalytic field of Au NCs. 相似文献
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基于各种电化学过程的能源转化技术是未来可持续能源利用和发展的关键, 而催化剂在其中扮演着非常重要的角色. 二维金属纳米材料因其独特的物理化学性质在许多电催化反应中都展现出巨大的应用潜力, 也因此受到了广泛关注. 本文介绍了二维金属纳米材料的常见合成方法与策略, 并综合评述了近年来该类材料在电催化应用领域中的研究进展, 重点探讨了材料的组分和微观结构等因素对其性能的影响机理, 最后对二维金属纳米材料目前所面临的挑战以及未来的研究方向进行了总结与展望. 相似文献
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Alain R. Puente Santiago Olivia Fernandez‐Delgado Ashley Gomez Md Ariful Ahsan Luis Echegoyen 《Angewandte Chemie (International ed. in English)》2021,60(1):122-141
An emerging class of heterostructures with unprecedented (photo)electrocatalytic behavior, involving the combination of fullerenes and low‐dimensional (LD) nanohybrids, is currently expanding the field of energy materials. The unique physical and chemical properties of fullerenes have offered new opportunities to tailor both the electronic structures and the catalytic activities of the nanohybrid structures. Here, we comprehensively review the synthetic approaches to prepare fullerene‐based hybrids with LD (0D, 1D, and 2D) materials in addition to their resulting structural and catalytic properties. Recent advances in the design of fullerene‐based LD nanomaterials for (photo)electrocatalytic applications are emphasized. The fundamental relationship between the electronic structures and the catalytic functions of the heterostructures, including the role of the fullerenes, is addressed to provide an in‐depth understanding of these emerging materials at the molecular level. 相似文献
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Low-dimensional high-entropy alloy (HEA) nanomaterials are widely employed as electrocatalysts for energy conversion reactions, due to their inherent advantages, including high electron mobility, rich catalytically active site, optimal electronic structure. Moreover, the high-entropy, lattice distortion, and sluggish diffusion effects also enable them to be promising electrocatalysts. A thorough understanding on the structure-activity relationships of low-dimensional HEA catalyst play a huge role in the future pursuit of more efficient electrocatalysts. In this review, we summarize the recent progress of low-dimensional HEA nanomaterials for efficient catalytic energy conversion. By systematically discussing the fundamentals of HEA and properties of low-dimensional nanostructures, we highlight the advantages of low-dimensional HEAs. Subsequently, we also present many low-dimensional HEA catalysts for electrocatalytic reactions, aiming to gain a better understanding on the structure-activity relationship. Finally, a series of upcoming challenges and issues are also thoroughly proposed as well as their future directions. 相似文献
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Hydrogen(H2) is considered to be a promising substitute for fossil fuels. Two-dimensional(2D) nanomaterials have exhibited an efficient electrocatalytic capacity to catalyze hydrogen evolution reaction(HER).Particularly, phase engineering of 2D nanomaterials is opening a novel research direction to endow 2D nanostructures with fascinating properties for deep applications in catalyzing HER. In this review, we briefly summarize the research progress and present the current challenges on... 相似文献
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Two-dimensional metal-organic frameworks (2D MOFs) inherently consisting of metal entities and ligands are promising single-atom catalysts (SACs) for electrocatalytic chemical reactions. Three 2D Fe-MOFs with NH, O, and S ligands were designed using density functional theory calculations, and their feasibility as SACs for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) was investigated. The NH, O, and S ligands can be used to control electronic structures and catalysis performance in 2D Fe-MOF monolayers by tuning charge redistribution. The results confirm the Sabatier principle, which states that an ideal catalyst should provide reasonable adsorption energies for all reaction species. The 2D Fe-MOF nanomaterials may render highly-efficient HER, OER, and ORR by tuning the ligands. Therefore, we believe that this study will serve as a guide for developing of 2D MOF-based SACs for water splitting, fuel cells, and metal-air batteries. 相似文献