Functionalization of Zirconium‐Based Metal–Organic Layers with Tailored Pore Environments for Heterogeneous Catalysis

Intriguing properties and functions are expected to implant into metal–organic layers (MOLs) to achieve tailored pore environments and multiple functionalities owing to the synergies among multiple components. Herein, we demonstrate a facile one‐pot synthetic strategy to incorporate multiple functionalities into stable zirconium MOLs via secondary ligand pillaring. Through the combination of Zr₆‐BTB (BTB=benzene‐1,3,5‐tribenzoate) layers and diverse secondary ligands (including ditopic and tetratopic linkers), 31 MOFs with multi‐functionalities were systematically prepared. Notably, a metal–phthalocyanine fragment was successfully incorporated into this Zr‐MOL system, giving rise to an ideal platform for the selective oxidation of anthracene. The organic functionalization of two‐dimensional MOLs can generate tunable porous structures and environments, which may facilitate the excellent catalytic performance of as‐synthesized materials.     

Functionalization of Zirconium-Based Metal–Organic Layers with Tailored Pore Environments for Heterogeneous Catalysis

Intriguing properties and functions are expected to implant into metal–organic layers (MOLs) to achieve tailored pore environments and multiple functionalities owing to the synergies among multiple components. Herein, we demonstrate a facile one-pot synthetic strategy to incorporate multiple functionalities into stable zirconium MOLs via secondary ligand pillaring. Through the combination of Zr₆-BTB (BTB=benzene-1,3,5-tribenzoate) layers and diverse secondary ligands (including ditopic and tetratopic linkers), 31 MOFs with multi-functionalities were systematically prepared. Notably, a metal–phthalocyanine fragment was successfully incorporated into this Zr-MOL system, giving rise to an ideal platform for the selective oxidation of anthracene. The organic functionalization of two-dimensional MOLs can generate tunable porous structures and environments, which may facilitate the excellent catalytic performance of as-synthesized materials.     

Controlled Reactivity Tuning of Metal‐Functionalized Vanadium Oxide Clusters

Controlling the assembly and functionalization of molecular metal oxides [M_xO_y]^n? (M=Mo, W, V) allows the targeted design of functional molecular materials. While general methods exist that enable the predetermined functionalization of tungstates and molybdates, no such routes are available for molecular vanadium oxides. Controlled design of polyoxovanadates, however, would provide highly active materials for energy conversion, (photo‐) catalysis, molecular magnetism, and materials science. To this end, a new approach has been developed that allows the reactivity tuning of vanadium oxide clusters by selective metal functionalization. Organic, hydrogen‐bonding cations, for example, dimethylammonium are used as molecular placeholders to block metal binding sites within vanadate cluster shells. Stepwise replacement of the placeholder cations with reactive metal cations gives mono‐ and difunctionalized clusters. Initial reactivity studies illustrate the tunability of the magnetic, redox, and catalytic activity.     

Simulation of conditions for fabrication of optical nanowaveguides in the form of chains of spherical metal nanoparticles by electrostatic functionalization of the process substrate

A method is proposed for electrostatic functionalization of substrates used to prepare ordered structures composed of closely spaced plasmon-resonant nanoparticles. The method ensures selective deposition of nanoparticles from the bulk of a colloidal system onto the substrates. This method is based on placing a metal nanotemplate of a required configuration at the opposite side of a substrate, with an electric potential being applied to the template. A mathematical model is developed to ensure that the system parameters responsible for the deposition of metal nanoparticles into ordered single-domain structures on the substrate from a bulk sol in a nonuniform electric field generated by the nanotemplate correspond to the real experimental conditions. Since the degree of imperfection of the synthesized chains governs the applicability of these structures to transmission of the optical excitation at the frequency of the surface plasmon of the particles, the dependence of the degree of imperfection on the physicochemical and electrical parameters of the system is studied using the Brownian-dynamics model. The calculations of the spectral and transmission properties of nanowaveguides of this type are exemplified.     

Electronically selective chemical functionalization of carbon nanotubes: correlation between Raman spectral and electrical responses

Single-walled carbon nanotubes (SWNTs) demonstrate remarkable electronic and mechanical properties useful in developing areas such as nanoelectromechanical systems and flexible electronics. However, the highly inhomogeneous electronic distribution arising from different diameters and chirality in any given as-synthesized SWNT samples imposes severe limitations. Recently demonstrated selective chemical functionalization methods may provide a simple scalable means of eliminating metallic tubes from SWNT transistors and electronic devices. Here, we report on combined electron transport and Raman studies on the reaction of 4-bromobenzene diazonium tetrafluoroborate directly with single and networks of SWNT transistors. First, Raman studies are carried out on isolated individual SWNTs grown on SiO2/Si substrates by chemical vapor deposition with and without metal contacts. Metallic tubes are found to have, on average, higher reactivity toward diazonium reagents. However, a considerable degradation of electrical properties of semiconducting tubes occurs if the reaction is carried out to the point where the conductivity of metallic tubes is significantly suppressed. Insights from single-tube studies are then applied to elucidate the electrical and the Raman responses of SWNT random network transistors of different channel lengths to chemical functionalization.     

New s-Block Metal Pyridinedicarboxylate Network Structures through Gas-Phase Thin-Film Synthesis

The combined atomic and molecular layer deposition (ALD/MLD) technique offers a unique way to build—both known and previously unknown—crystalline coordination polymer materials directly from gaseous precursors in a high-quality thin-film form. Here, we demonstrate the ALD/MLD of crystalline Li-, Na-, and K-based 3,5-pyridinedicarboxylate (3,5-PDC) thin films; the Li₂-3,5-PDC films are of the known Li-ULMOF-4 crystal structure whereas the other as-deposited crystalline films possess structures not previously reported. Another exciting possibility offered by ALD/MLD is the deposition of well-defined but amorphous metal–organic thin films, such as our Mg-, Ca-, Sr-, and Ba-based 3,5-PDC films, which can then be crystallized into water-containing structures through a post-deposition humidity treatment. All together, the new metal–organic structures realized in this study through ALD/MLD comprise a majority of the (anhydrous and water-containing) members of the s-block metal 3,5-pyridinedicarboxylate family.     

Versatile Fabrication of Intact Three-Dimensional Metallic Butterfly Wing Scales with Hierarchical Sub-micrometer Structures

Spread your wings: Surface functionalization of butterfly wing scales and subsequent electroless deposition of different metals produces metallic replicas with 3D sub-micrometer structures. This approach converts complicated natural 3D bioorganic structures into various otherwise unavailable metal structures with optical, electronic, magnetic, thermal, or catalytic applications.     

Decoration of Graphitic Surfaces with Sn Nanoparticles through Surface Functionalization Using Diazonium Chemistry

Composites of tin nanoparticles (Sn NP) and graphene are candidate materials for high capacity and mechanically stable negative electrodes in rechargeable Li ion batteries. A uniform dispersion of Sn NP with controlled size is necessary to obtain high electrochemical performance. We show that the nucleation of Sn particles on highly ordered pyrolitic graphite (HOPG) from solution can be controlled by functionalizing the HOPG surface by aryl groups prior to Sn deposition. On the contrary, we observe heterogeneous deposition of micrometer sized Sn islands on HOPG subjected to oxidation prior to deposition in the same conditions. We demonstrate that functional groups act as nucleation sites for Sn NP nucleation, and that homogeneous nucleation of small particles can be achieved by combining surface functionalization with diazonium chemistry and appropriate stabilizers in solution.     

静电纺纳米纤维基超级电容器无粘合剂电极材料的研究进展

对高性能超级电容器不断增长的需求促进了无粘合剂电极材料的快速发展。静电纺纳米纤维由于具有良好的柔性、大比表面积、高孔隙率、容易制备等优点引起了研究者们的强烈关注。本文综述了静电纺纳米纤维基无粘合剂电极材料在超级电容器领域的研究进展,阐述了不同材料的设计制备过程和提升电化学性能的诸多方法,并指明了静电纺纳米纤维基超级电容器无粘合剂电极材料的发展机遇与挑战,为性能优异的无粘合剂超级电容器电极材料的进一步开发与应用拓宽了思路。     

金属-有机骨架材料及其在催化反应中的应用

金属-有机骨架(metal-organic frameworks, MOFs)材料是由金属离子和有机配体通过自组装而成的具有多孔结构的特殊晶体材料。由于其种类的多样性、孔道的可调性和结构的易功能化,已在气体的吸附和分离、催化、磁学、生物医学等领域表现出了诱人的应用前景。本文介绍了MOFs材料的类型和常用的合成方法,综述了近年来MOFs材料在催化领域的应用,特别是以MOFs材料中骨架金属作为活性中心、骨架有机配体作为活性中心和负载催化活性组分的催化反应,并对MOFs材料的催化应用趋势做了展望,以期对MOFs材料的催化性能有比较全面的认识。     

Postsynthetic Functionalization of DNA-Nanocomposites with Proteins Yields Bioinstructive Matrices for Cell Culture Applications

We report on the directed postsynthetic functionalization of soft DNA nanocomposite materials with proteins. Using the example of the functionalization of silica nanoparticle-modified DNA polymer materials with agonists or antagonists of the epidermal growth factor receptor EGFR cell membrane receptor, we demonstrate that hierarchically structured interfaces to living cells can be established. Owing to the modular design principle, even complex DNA nanostructures can be integrated into the materials, thereby enabling the high-precision arrangement of ligands on the lower nanometer length scale. We believe that such complex biohybrid material systems can be used for new applications in biotechnology.     

Advanced chemical design with supported metal complexes for selective catalysis

This review covers several recent topics of novel catalyst design with supported metal complexes on oxide surfaces for selective catalysis such as chiral self-dimerization to create asymmetric oxidative coupling catalysis, surface functionalization with achiral reagents to promote asymmetric catalysis, and molecular imprinting to design shape-selective catalysis. The new concepts and designs find wide applications to a variety of selective catalysts.     

Electrodeposition in Ionic Liquids

Due to their attractive physico‐chemical properties, ionic liquids (ILs) are increasingly used as deposition electrolytes. This review summarizes recent advances in electrodeposition in ILs and focuses on its similarities and differences with that in aqueous solutions. The electrodeposition in ILs is divided into direct and template‐assisted deposition. We detail the direct deposition of metals, alloys and semiconductors in five types of ILs, including halometallate ILs, air‐ and water‐stable ILs, deep eutectic solvents (DESs), ILs with metal‐containing cations, and protic ILs. Template‐assisted deposition of nanostructures and macroporous structures in ILs is also presented. The effects of modulating factors such as deposition conditions (current density, current density mode, deposition time, temperature) and electrolyte components (cation, anion, metal salts, additives, water content) on the morphology, compositions, microstructures and properties of the prepared materials are highlighted.     

Immobilized Molybdovanadophosphoric Acid for Selective Oxidations

In this review, we have summarized our work on the immobilization of molybdovanadophosphoric acids onto mesoporous silica and mesoporous carbon by different approaches such as amine functionalization and ionic liquid functionalization. All catalyst materials were well characterized by various ex-situ and in situ techniques for their structural integrity and physico-chemical properties. These materials were tested in different selective oxidation processes to develop environmentally benign protocols for the synthesis of fine chemicals and tried to study their mechanisms.     

Conformational adaptation and selective adatom capturing of tetrapyridyl-porphyrin molecules on a copper (111) surface

We present a combined low-temperature scanning tunneling microscopy and near-edge X-ray adsorption fine structure study on the interaction of tetrapyridyl-porphyrin (TPyP) molecules with a Cu(111) surface. A novel approach using data from complementary experimental techniques and charge density calculations allows us to determine the adsorption geometry of TPyP on Cu(111). The molecules are centered on "bridge" sites of the substrate lattice and exhibit a strong deformation involving a saddle-shaped macrocycle distortion as well as considerable rotation and tilting of the meso-substituents. We propose a bonding mechanism based on the pyridyl-surface interaction, which mediates the molecular deformation upon adsorption. Accordingly, a functionalization by pyridyl groups opens up pathways to control the anchoring of large organic molecules on metal surfaces and tune their conformational state. Furthermore, we demonstrate that the affinity of the terminal groups for metal centers permits the selective capture of individual iron atoms at low temperature.     

Controlled polymerization in mesoporous silica toward the design of organic-inorganic composite nanoporous materials

Free-radical polymerization inside mesoporous silica has been investigated in order to open a route to functional polymer-silica composite materials with well-defined mesoporosity. Various vinyl monomers, such as styrene, chloromethyl styrene, 2-hydroxyethyl methacrylate, and methacrylic acid, were polymerized after impregnation into mesoporous silicas with various structures, which were synthesized using polyalkylene oxide-type block copolymers. The location of the polymers was systematically controlled with detailed structures of the silica framework and the polymerization conditions. Particularly noteworthy is the polymer-silica composite structure obtained by in situ polymerization after the selective adsorption of monomers as a uniform film on silica walls. The analysis of XRD data and the N(2) adsorption isotherms indicates the formation of uniform polymer nanocoating. The resultant polymer-silica composite materials can easily be post-functionalized to incorporate diverse functional groups in high density, due to the open porous structure allowing facile access for the chemical reagent. The fundamental characteristics of the composite materials are substantiated by testing the biomolecule's adsorption capacity and catalytic reactivity. Depending on the structure and composition of polymers, the resultant polymer-silica composite materials exhibit notably distinct adsorption properties toward biomolecules, such as proteins. Furthermore, it is demonstrated that the nanocoatings of polymers deposited on the mesopore walls have remarkably enhanced catalytic activity and selectivity, as compared to that of bulk polymer resins. We believe that, due to facile functionalization and attractive textural properties, the mesoporous polymer-silica composite materials are very useful for applications, such as adsorption, separation, host-guest complexes, and catalysis.     

Site‐Selective Oxidation of Monolayered Liquid‐Exfoliated WS2 by Shielding the Basal Plane through Adsorption of a Facial Amphiphile

In recent years, various functionalization strategies for transition‐metal dichalcogenides have been explored to tailor the properties of materials and to provide anchor points for the fabrication of hybrid structures. Herein, new insights into the role of the surfactant in functionalization reactions are described. Using the spontaneous reaction of WS₂ with chloroauric acid as a model reaction, the regioselective formation of gold nanoparticles on WS₂ is shown to be heavily dependent on the surfactant employed. A simple model is developed to explain the role of the chosen surfactant in this heterogeneous functionalization reaction. The surfactant coverage is identified as the crucial element that governs the dominant reaction pathway and therefore can severely alter the reaction outcome. This study shows the general importance of the surfactant choice and how detrimental or beneficial a certain surfactant can be to the desired functionalization.     

Innovative Materials for Energy Storage and Conversion

The metal chalcogenides (MCs) for sodium-ion batteries (SIBs) have gained increasing attention owing to their low cost and high theoretical capacity. However, the poor electrochemical stability and slow kinetic behaviors hinder its practical application as anodes for SIBs. Hence, various strategies have been used to solve the above problems, such as dimensions reduction, composition formation, doping functionalization, morphology control, coating encapsulation, electrolyte modification, etc. In this work, the recent progress of MCs as electrodes for SIBs has been comprehensively reviewed. Moreover, the summarization of metal chalcogenides contains the synthesis methods, modification strategies and corresponding basic reaction mechanisms of MCs with layered and non-layered structures. Finally, the challenges, potential solutions and future prospects of metal chalcogenides as SIBs anode materials are also proposed.     

DNA based multi-copper ions assembly using combined pyrazole and salen ligandosides

The DNA structure is an ideal building block for the construction of functional nano-objects. In this direction, metal coordinating base pairs (ligandosides) are an appealing tool for the future specific functionalization of such nano-objects. We present here a study, in which we combine the metal ion coordinating pyrazole ligandoside with the interstrand crosslinking salen ligandoside system. We show that both ligandosides, when combined, are able to create stable multi-copper ion complexing DNA double helix structures in a cooperative fashion.     

Selective nucleation and growth of metal-organic open framework thin films on patterned COOH/CF3-terminated self-assembled monolayers on Au(111)

Metal-Organic open Framework coordination polymers (MOFs) are a fascinating class of materials. We demonstrate the selective growth of patterned thin films of MOF-5 and the subsequent loading with a palladium organic compound, which acts as a precursor for the deposition of palladium nanoclusters inside the cavities of the MOF-5 material.