Engineering transition metal-based nanomaterials for high-performance electrocatalysis

Transition metal(TM)based electrocatalysts attract increasing attention in energy conversion reactions,and current effects focus on material engineering strategies to tailor physicochemical properties of TM based electrocatalysts for improved performance.This review provides a summary about the recent advances of engineering TM based nanomaterials for electrocatalytic reactions,which include hydrogen evolution reaction(HER),oxygen evolution reaction(OER),CO2 reduction reaction(CO2RR),and nitrate reduction reaction(NO3RR).We highlight four engineering strategies,namely,size engineering,facet engineering,composition engineering,and crystal structure engineering for TM based electrocatalysts,and pay a special emphasis on exploring the relationship between their physicochemical properties and catalytic activities.We outline the opportunities in this research field,in particular,the strategy of rationally combining in-situ and operando techniques and theoretical predication to design efficient electrocatalysts.Finally,issues that deserve attention and consideration for practical applications are discussed.

Electrodeposition:Synthesis of advanced transition metal-based catalyst for hydrogen production via electrolysis of water

Developing lower-cost and higher-effective catalyst to support hydrogen(H_(2))production by electrochemical water-splitting has been recognized as a preferred strategy to drive the clean energy utilization.As a credible technology for the synthesis of functional materials,electrodeposition has attracted widespread attention,especially suitable for non-noble transition metal-based catalysts(TMCs).Recently,lots of researchers have been devoted to this hot research direction with plentiful achievements,however,a comprehensive review towards this area is still missing.Hence,we summarize the past research progress,presents the technical characteristics of electrodeposition from the viewpoint of fundamental theory and influence factors for the electrochemical deposition behavior,and introduce its application in various of TMCs with versatile nanostructures and compositions.Except a deeper and more comprehensive cognition of electrodeposition,we further discuss the catalyst’s optimized hydrogen evolution reaction(HER),oxygen evolution reaction(OER)performance as well as overall water splitting that combined with the synthetic process.Finally,we conclude the technical advantages towards electrodeposition,propose challenge and future research directions in this promising field.This timely review aims to promote a deeper understanding of effective catalysts obtained via electrodeposition strategy,and provide new guidance for the design and synthesis of future catalysts for hydrogen production.

High pressure structural phase transitions of TiO_2 nanomaterials

Recently, the high pressure study on the TiO_2 nanomaterials has attracted considerable attention due to the typical crystal structure and the fascinating properties of TiO_2 with nanoscale sizes. In this paper, we briefly review the recent progress in the high pressure phase transitions of TiO_2 nanomaterials. We discuss the size effects and morphology effects on the high pressure phase transitions of TiO_2 nanomaterials with different particle sizes, morphologies, and microstructures. Several typical pressure-induced structural phase transitions in TiO_2 nanomaterials are presented, including size-dependent phase transition selectivity in nanoparticles, morphology-tuned phase transition in nanowires, nanosheets,and nanoporous materials, and pressure-induced amorphization（PIA） and polyamorphism in ultrafine nanoparticles and TiO_2-B nanoribbons. Various TiO_2 nanostructural materials with high pressure structures are prepared successfully by high pressure treatment of the corresponding crystal nanomaterials, such as amorphous TiO_2 nanoribbons, α-PbO_2-type TiO_2 nanowires, nanosheets, and nanoporous materials. These studies suggest that the high pressure phase transitions of TiO_2 nanomaterials depend on the nanosize, morphology, interface energy, and microstructure. The diversity of high pressure behaviors of TiO_2 nanomaterials provides a new insight into the properties of nanomaterials, and paves a way for preparing new nanomaterials with novel high pressure structures and properties for various applications.

Recent Advances in Transition Metal-Based Catalysts for Electrocatalytic Nitrate Reduction Reaction

The accumulation of excessive nitrate in the atmosphere not only jeopardizes human health but also disrupts the balance of the nitrogen cycle in the ecosystem.Among various nitrate removal technologies,electrocatalytic nitrate reduction reaction(eNO_(3)RR)has been widely studied for its advantages of being eco-friendly,easy to operate,and controllable under environmental conditions with renewable energy as the driving force.Transition metal-based catalysts(TMCs)have been widely used in electrocatalysis due to their abundant reserves,low costs,easy-to-regulate electronic structure and considerable electrochemical activity.In addition,TMCs have been extensively studied in terms of the kinetics of the nitrate reduction reaction,the moderate adsorption energy of nitrogen-containing species and the active hydrogen supply capacity.Based on this,this review firstly discusses the mechanism as well as analyzes the two main reduction products(N_(2)and NH_(3))of eNO_(3)RR,and reveals the basic guidelines for the design of efficient nitrate catalysts from the perspective of the reaction mechanism.Secondly,this review mainly focuses on the recent advances in the direction of eNO_(3RR)with four types of TMCs,Fe,Co,Ni and Cu,and unveils the interfacial modulation strategies of Fe,Co,Ni and Cu catalysts for the activity,reaction pathway and stability.Finally,reasonable suggestions and opportunities are proposed for the challenges and future development of eNO_(3)RR.This review provides far-reaching implications for exploring cost-effective TMCs to replace high-cost noble metal catalysts(NMCs)for eNO_(3)RR.

Recent advances in the design of biosensors based on novel nanomaterials:An insight

Biosensors have acquired much importance in drug discovery,medical diagnostics,food safety,defense,security,and monitoring of environmental conditions.Furthermore,there has been great progress in the potential applications of advanced nanomaterials in biosensors.Every year there are several advances in sensing techniques that can be attributed to nanomaterials,biorecognition elements,or their related fabrication techniques.The further development of nanotechnology-based sensors provides a wide variety of opportunities to modern research.Advanced nanomaterials can provide remarkable optical,electrical,mechanical,and catalytic properties.For example,transition metals and organic polymers have been used in the fabrication of powerful,sensitive,and precise biosensors.The distinctive properties of advanced nanomaterials have been widely incorporated into biosensors.However,fabrication techniques also play important roles in the development of these devices.Therefore,we present a review of some of the advanced nanomaterials that have been widely used over the last few years and discuss their fabrication techniques.The focus of this review is to provide a directional perspective of recently fabricated advanced nanomaterial-based biosensors in the diagnosis of various diseases.

Applications of Transition Metal(Fe,Co,Ni)-Based Metal–Organic Frameworks and their Derivatives in Batteries and Supercapacitors

Metal–organic frameworks(MOFs),which are generally considered to be crystalline materials comprising metal centers and organic ligands,have attracted growing attention because of their controllable structures and high porosity.MOFs based on transition metals(Fe,Co,Ni)are highly effi cient electrode materials for electrochemical energy storage.In this review,the characteristics of Fe-MOFs,Co-MOFs,Ni-MOFs,and their derivatives are summarized,and the relationships between the structures and performance are unveiled in depth.Additionally,their applications in lithium–ion batteries,lithium–sulfur batteries,and supercapacitors are discussed.This review sheds light on the development of MOFs and their derivatives to realize excellent electrochemical performance.

过渡金属低维纳米材料在电催化领域中的研究进展

随着环境问题的日趋严重和能源危机的不断攀升,利用电催化技术开发可持续的绿色新能源迫在眉睫。过渡金属低维纳米材料具有高活性表面、高效的电子转移速率和丰富的表面空位,能够有效提升电催化反应的效率和稳定性。本文基于材料维数,将过渡金属低维纳米材料分类,并分别阐明其优势,重点综述零维、一维、二维纳米材料在电催化领域中的研究成果,揭示低维纳米结构与电催化活性、稳定性之间的关系,明确了低维纳米化是提高电催化性能的有效方法。最后,指出过渡金属低维纳米催化剂应根据需求合理设计并优化其结构。未来低维纳米催化剂的发展方向应是基础研究与计算研究相结合,用理论来引导设计,搭配机器学习预先选择合适的结构模型以及朝着改进现有材料结合更多更高效的复合材料进一步发展。

新型油井水泥用纳米基促凝早强剂

针对传统油井水泥促凝剂存在的腐蚀套管、增稠及早强作用较弱等问题,根据结构设计,通过溶液法合成了一种新型纳米基促凝早强剂A-1,并对其综合性能及作用机理进行了研究探讨。实验表明,该纳米基促凝早强剂在改善水泥浆流变的同时可显著缩短中低温下水泥浆的稠化时间,明显加快水泥石强度发展,稠化时间之比可达0.33,起强度时间可缩短50%,6 h抗压强度可达净浆的5倍以上,后期强度提高率仍可达29%。此外,该纳米基促凝早强剂还可明显缩短水泥浆静胶凝过渡时间,表现出良好的防窜作用。微观分析表明,该纳米基促凝早强剂可通过成核模板效应改变水泥石微观形貌,加速水泥石水化,使水泥石更加致密,从而改善水泥石力学性能。

Metal-based cathode catalysts for electrocatalytic ORR in microbial fuel cells:A review

Microbial fuel cells(MFCs)have a simple structure and excellent pollutant treatment and power generation performance.However,the slow kinetics of the oxygen reduction reaction(ORR)at the MFC cathode limit power generation.The electrochemical performance of MFCs can be improved through electrocatalysis.Thus far,metal-based catalysts have shown astonishing results in the field of electrocatalysis,enabling MFC devices to demonstrate power generation capabilities comparable to those of Pt,thus showing enormous potential.This article reviews the research progress of meta-based MFC cathode ORR catalysts,including the ORR reaction mechanism of MFC,different types of catalysts,and preparation strategies.The catalytic effects of different catalysts in MFC are compared and summarized.Before discussing the practical application and expanded manufacturing of catalysts,we summarize the key challenges that must be addressed when using metal-based catalysts in MFC,with the aim of providing a scientific direction for the future development of advanced materials.

α-Fe_(2)O_(3)@SiO_(2)@Cu_(2)O核壳结构复合物的合成及其光催化性质的研究

采用水热法,以FeCl_(3)·6H_(2)O和NaH_(2)PO_(4)·2H2O为原料,制备了α-Fe_(2)O_(3)纳米颗粒,然后以TEOS作为硅源,CTAB作为造孔剂,制备α-Fe_(2)O_(3)包覆SiO_(2)的介孔材料,然后对SiO_(2)包覆的α-Fe_(2)O_(3)掺杂过渡金属Cu_(2)O,得到α-Fe_(2)O_(3)@SiO_(2)@Cu_(2)O核壳结构复合物,并且利用XRD对制备的产品进行表征,进行光催化活性的评价。结果表明,以高压汞灯为光源,亚甲基蓝浓度为15 mg/L,当催化剂用量为5 mg,90 min的降解率达到47.3%。

Transition metal-based electrocatalysts for overall water splitting

Electrochemical overall water splitting is attracting a broad focus as a promising strategy for converting the electrical output of renewable resources into chemical fuels,specifically oxygen and hydrogen.However,the urgent challenge in water electrolysis is to search for low-cost,high-efficiency catalysts based on earth-abundant elements as an alternative to the high-cost but effective noble metal-based catalysts.The transition metal-based catalysts are more appealing than the noble metal catalysts because of its low cost,high performance and long stability.Some recent advances for the development in overall water splitting are reviewed in terms of transition metal-based oxides,carbides,phosphides,sulfides,and hybrids of their mixtures as hybrid bifunctional electrocatalysts.Concentrating on different catalytic mechanisms,recent advances in their structural design,controllable synthesis,mechanistic insight,and performance-enhancing strategies are proposed.The challenges and prospects for the future development of transition metal-based bifunctional electrocatalysts are also addressed.©2021 Chinese Chemical Society and Institute of Materia Medica,Chinese Academy of Medical Sciences.

Basic deep eutectic solvents as reactant, template and solvents for ultra-fast preparation of transition metal oxide nanomaterials

Developing a new type of deep eutectic solvents(DESs)is indispensable for expanding their application in various fields.Here,we report a series of new highly basic DESs.FT-IR,quantitative 1 H NMR,MD simulation and physical properties show that these basic liquids are made up of hydroxide acceptor of alkali metal hydroxides in which the hydrogen bonding interactions coordinate the donor.These DESs can be played three roles as new solvents,template and reactant for facile and ultra-fast preparation of transition metal oxide nanomaterials such as NiCo2 O4,MnCo2 O4,NiMn2 O4,CoCu2 O4 and Co3 O4 under mild condition.This work shows one of the low energy-intensive methods for nanomaterial preparation.These initial findings of basic deep eutectic solvents provide a potential applicability around the systematic development of transition metal oxide nanosheets.

Two-dimensional transition metal chalcogenide nanomaterials for cancer diagnosis and treatment

For more than a decade,the exfoliation of graphene and other layered materials has led to a tremendous amount of research in two-dimensional(2D)materials,among which 2D transition metal chalcogenides(TMCs)nanomaterials have attracted much attention in a wide range of applications including photoelectric devices,lithium-ion batteries,catalysis,and energy conversion and storage owing to their unique photoelectric physical properties.With such large specific surface area,strong near-infrared(NIR)absorption and abundant chemical element composition,2D TMCs nanomaterials have become good candidates in biomedical imaging and cancer treatment.This review systematically summarizes recent progress on 2D TMCs nanomaterials,which includes their synthesis methods and applications in cancer treatment.At the end of this review,we also highlight the future prospects and challenges of 2D TMCs nanomaterials.It is expected that this work can provide the readers with a detailed overview of the synthesis of 2D TMCs and inspire more novel functional biomaterials based on 2D TMCs for cancer treatment in the future.

g-C_(3)N_(4)/过渡金属硫化物复合材料的结构设计、合成及光催化应用

作为一种无机非金属半导体光催化材料,石墨相氮化碳(g-C_(3)N_(4))由于具有独特的能带结构和晶体结构特征,在环境治理和清洁能源领域受到了广泛的关注。然而单一相g-C_(3)N_(4)存在对太阳光的响应范围偏小、比表面积小、反应活性位点少和光生电子-空穴对易复合等问题,限制了其在光催化领域的大规模使用。过渡族金属硫化物具有特殊的能带结构和优异的物理化学性质,在光催化应用中表现出较大的发展潜力。基于光催化材料当前存在的光响应范围窄、光生载流子易于复合导致光催化量子效率低、光生载流子存续时间短和反应活性位不足等问题,研究者们普遍专注于异质结尤其是Z型异质结的构建,以期解决上述问题。本文综述了g-C_(3)N_(4)和过渡金属硫化物光催化材料的性能优缺点、结构设计及反应机理等,重点梳理了异质结的构建进展情况,并展望了g-C_(3)N_(4)/过渡金属硫化物复合材料的发展前景。

Liquid metal-based textiles for smart clothes

The smart clothes emerge as a new generation of garments developed in the scientific and industrial communities,gaining increasing attention due to the real-time responses to exterior environments or stimuli.Owing to the unique merits of liquid metal(LM)such as excellent fluidity,high conductivity and intrinsic stretchability in ambient environment,LM-based smart textiles are widely applied in chemical sensors,wearable electronics and stretchable devices.This review is dedicated to summarizing different preparation methods and functions of LM-based textiles(LMTs)for smart clothes,which consists of the design principles,the fabrication strategies,the working mechanism of LMTs,and the tremendous applications sorted by the features of LM.Typical methods of the synthesis to build LMTs are divided into two domains classified by spatial arrangement.One strategy is the exterior decoration with LM,while the other is interior encapsulation of LM.Moreover,the primary applications of LMT-based smart clothes have been illustrated through the utilization of the properties of LM matrix.The categorization of LMTs aims to facilitate further investigation and research in the future development of LM-based smart clothes.Finally,future prospects and opportunities of LMT-based smart clothes are discussed in this area.

在酸性环境中非贵金属析氧反应电催化剂现状及发展趋势

质子交换膜(PEM)电解水槽是最有前途的制氢技术之一,其阳极上发生的析氧反应(OER)的缓慢四电子过程决定了整体效率。因此,开发高活性且稳定的电催化剂用于酸性环境下的OER是一个长期的挑战。目前,PEM电解水槽中的阳极或电催化剂多使用贵金属铱、钌及其氧化物,它们不仅在强酸性条件下表现出较差的稳定性,而且成本较高、地壳储量低,极大地阻碍了其商业化应用。因此,在酸性介质下,开发活性高,稳定性良好,价格低廉的非贵金属OER电催化剂对PEM电解槽的大规模应用具有重要的意义。综述了当前常见的各种非贵金属电催化剂,包括过渡金属氧化物、碳基材料和其他类型化合物,并对各类催化剂的优缺点进行了讨论,并提出了酸性OER非贵金属电催化剂的未来发展方向。

一种新型相变蓄热材料的实验研究

将有机相变蓄热材料与导热系数高的无机物进行纳米复合的创新方法 ,克服现有有机蓄能材料存在液体渗漏、传热率低、相变时体积变化、有可燃性、对母体材料有副作用以及无机蓄能材料存在腐蚀性、相变过程中具有过冷和反相等缺点 ,将有机相变材料嵌入到导热系数较高的二氧化硅纳米层空间内 ,制备有机无机纳米复合相变蓄热材料。采用扫描电镜、红外光谱分析仪、差示扫描量热分析仪、导热系数仪分析制备的复合相变材料 ,结果表明 ,复合相变材料是多孔纳米复合材料 ,其蓄热能力较好、导热性能好。

纳米改性再生骨料混凝土破坏机理研究

对再生骨料混凝土(RAC)进行了裂纹演变规律和不同掺量的纳米硅溶胶、纳米碳酸钙改性试验研究.采用高速摄像仪实时观测了不同水灰比(mW/mC=0.4,0.5和0.6)和不同再生骨料替代率下再生骨料混凝土试块单轴受压加载过程中的裂纹开展信息,对不同纳米材料改性的RAC进行了扫描电镜和压汞测试,并对其界面过渡区的微观形貌和孔结构进行了对比分析.结果表明:RAC的受压破坏大多为新老界面过渡区破坏,裂纹往往最先由此处开展,具体开裂位置取决于新老砂浆的相对强度;裂纹围绕再生骨料周边逐步向四周扩展和贯通,最终导致试块纵向劈裂破坏;纳米硅溶胶能够很好地改善RAC界面过渡区微观结构,提高RAC抗压强度,而纳米碳酸钙难以进入RAC的界面过渡区,很难有效改善界面孔结构,因此未能明显提高RAC抗压强度.

PCT纳米材料结构相变的变温拉曼光谱研究

采用溶胶－凝胶法制备了（Ｐｂ１－ｘＣａｘ）ＴｉＯ３（ＰＣＴ（ｘ））纳米晶粉和纳米薄膜。变温拉曼光谱显示ＰＣＴ（０）和 ＰＣＴ（２０）从铁电四方相向顺电立方相的转变温度分别降低至４３０℃和３３０℃；结果同时表明ＰＣＴ（０）和ＰＣＴ（２０）薄 膜的声子频率发生一定程度的红移或蓝移，这归因于纳米材料掺杂引起的诱导效应和晶粒尺寸效应。

过渡金属掺杂磁性纳米粒子在生物医学领域中的研究进展

在过去50多年中,磁性纳米粒子(MNPs)由于其可协调的磁性、非侵入性、易操控性和良好的生物相容性等优点得到了广泛的关注。从具有复合结构或不同形状的MNPs的合成方法到与MNPs相关的大量表征技术,其应用领域也与我们的生活紧密相关。然而,MNPs的复杂磁行为受到多种参量的影响,包括粒径、成分、形状和结构等。基于此,通过调节MNPs的主要参量提高其磁功能效果对后续的材料设计和应用具有重大的参考意义。其中,二价过渡金属离子的掺杂是影响MNPs各种磁性能(如磁矩(μ)、饱和磁化强度(M_(s))、矫顽力(H_(c))、磁晶各向异性(K)和弛豫时间(τ_(N)和τ_(B))等)重要参量之一。因此,本文着重介绍了通过向磁性纳米材料中掺杂过渡金属离子来精确调控其磁性的相关机理研究,并介绍了掺杂过渡金属离子的MNPs在生物成像检测(磁共振成像和磁性粒子成像)、药物精准递送和肿瘤治疗以及生物传感方面的潜在机制和所取得的最新进展,最后总结了目前MNPs所面临的一些挑战以及未来发展的趋势。