Single-wall carbon nanotubes (SWCNTs), especially in the form of large-area and high-quality thin films, are a promising material for use in flexible and transparent electronics. Here, a continuous synthesis, deposition, and transfer technique is reported for the fabrication of meter-scale SWCNT thin films, which have an excellent optoelectrical performance including a low sheet resistance of 65 Ω/◽ with a transmittance of 90% at a wavelength of 550 nm. Using these SWCNT thin films, high-performance all-CNT thin-film transistors and integrated circuits are demonstrated, including 101-stage ring oscillators. The results pave the way for the future development of large-scale, flexible, and transparent electronics based on CNT thin films.

No abstract

By introducing the unprecedented and flexible isomeric bis(pyridyl-tetrazole) ligands into a polyoxometalates (POMs) system, three POM-based compounds, {Ag2(4-bptzb)2(H2O)2[H2PMo12O40]2}·4-bptzb·5H2O (1), [Ag4(3-bptzb)2(PMo(V)Mo(VI)11O40)]·2H2O (2), and Ag3(3-bptzb)2.5(H2O)2[H3P2W18O62] (3) [4-bptzb = 1,4-bis(5-(4-pyridyl)tetrazolyl)butane and 3-bptzb =1,4-bis(5-(3-pyridyl)tetrazolyl)butane], were synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analyses. Compound 1 exhibits a dimeric structure constructed from two Keggin [PMo12O40](3-) anions and a binuclear [Ag2(trans-4-bptzb)2](2+) subunit in which the trans-4-bptzb acts as a bidentate bridging ligand with one tetrazolyl group. In 2, the 3-bptzb acts as a tetradentate bridging ligand with the tetrazolyl and pyridyl groups linking Ag(I) ions to generate a 3D metal-organic framework (MOF), which contains charming meso-helix chains. The Keggin anions acting as bidentate inorganic ligands reside in the distorted tetragonal channels of the MOF. In compound 3, the 3-bptzb adopts versatile coordination modes linking Ag(I) ions to first construct loop connecting loop 1D chains, which are linked by {Ag[P2W18O62]}n zigzag chains to form a scarce hamburger-style 2D sheet. These adjacent sheets are further fused by 3-bptzb ligands to construct a 3D framework. The influences of isomeric bptzb ligands and POMs on the construction of Ag-bptzb subunits and the whole structures of the title compounds are discussed. The electrochemical behaviors and electrocatalytic activities of compounds 2 and 3 and their corresponding parent POMs as well as the fluorescent properties of the title compounds have been studied in detail. In addition, the photocatalytic activities of compounds 2 and 3 and their corresponding parent POMs for decomposition of methylene blue, rhodamine B, and methyl orange under UV irradiation have also been investigated.

A series of multifunctional Cu(II) metal-organic coordination polymers based on three flexible bis-pyridyl-bis-amide ligands and four aromatic dicarboxylates, namely [Cu(3-dpye)(3-NPA)(H2O)]·3H2O (1), [Cu(3-dpye)0.5(5-AIP)(H2O)] (2), [Cu(3-dpye)(1,3-BDC)]·3H2O (3), [Cu3(3-dpye)(1,2-BDC)2(μ2-OH)2] (4), [Cu3(3-dpyb)(1,2-BDC)2(μ2-OH)2] (5), [Cu(3-dpyh)0.5(1,2-BDC)]·H2O (6), [Cu(3-dpyh)0.5(5-AIP)(H2O)] (7) [3-dpye = N,N'-bis(3-pyridinecarboxamide)-1,2-ethane, 3-dpyb = N,N'-bis(3-pyridinecarboxamide)-1,4-butane, 3-dpyh = N,N'-bis(3-pyridinecarboxamide)-1,6-hexane, 3-H2NPA = 3-nitrophthalic acid, 5-H2AIP = 5-aminoisophthalic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, 1,2-H2BDC = 1,2-benzenedicarboxylic acid], have been hydrothermally synthesized and structurally characterized by elemental analyses, IR, PXRD, TG and single crystal X-ray diffraction. X-ray analyses reveal that the seven Cu(II) complexes show three kinds of different 2D layer structures (for complexes 1, 2, 3, 6 and 7) and a 3D coordination framework (for complexes 4 and 5), exhibiting the (4(4)·6(2)) topology for 1, (4(2)·6(3)·8)(4(2)·6) topology for isostructural complexes 2 and 7, (4(2)·6(7)·8)(4(2)·6) topology for complex 3, (3·4·5)2(3·4(2)·5·8(6))2(3(2)·8·9(2)·10)(4(2)·8(2)·10(2)) topology for isostructural complexes 4 and 5, and the (4(2)·6(3)·8)(4(2)·6) topology for complex 6, respectively. In complexes 1-7, the bis-pyridyl-bis-amide ligands adopt a μ2-bridging mode in 1, 2, 3, 6 and 7 (via ligation of two pyridyl nitrogen atoms) and a μ4-bridging coordination mode in 4 and 5 (via ligation of two pyridyl nitrogen atoms and two carbonyl oxygen atoms), which play an important role in determining the dimensionality of the title complexes. The aromatic dicarboxylates serve as a linker (for 1) and three-connected nodes (for 2-7) to bridge the adjacent Cu(II) ions, respectively, leading to the formation of various topological structures, which indicate both the substitute group and position of carboxyl group of the dicarboxylates play significant roles in the construction of the title complexes. The fluorescent, electrochemical and photocatalytic properties of complexes 1-7 have also been investigated.

A flexible single-wall carbon nanotube film prepared by simple filtration exhibited excellent adsorption of organic dyes under ultraviolet light in which a photodegradation-induced electrostatic interaction plays an important role.

A nitrogen-doped mesoporous carbon containing a network of carbon nanotubes (CNTs) was produced for use as a catalyst for the oxygen reduction reaction (ORR). SiO2 nanoparticles were decorated with clusters of Fe atoms to act as catalyst seeds for CNT growth, after which the material was impregnated with aniline. After polymerization of the aniline, the material was pyrolysed and the SiO2 was removed by acid treatment. The resulting carbon-based hybrid also contained some Fe from the CNT growth catalyst and was doped with N from the aniline. The Fe-N species act as active catalytic sites and the CNT network enables efficient electron transport in the material. Mesopores left by the removal of the SiO2 template provide short transport pathways and easy access to ions. As a result, the catalyst showed not only excellent ORR activity, with 59 mV more positive onset potential and 30 mV more positive half-wave potential than a Pt/C catalyst, but also much longer durability and stronger tolerance to methanol crossover than a Pt/C catalyst.

Thirteen new Cu II coordination polymers, namely, (1,3,5-HBTC)] ( 1), hexane, 1,3,5-H 3 BTC = 1,3,5-benzenetricarboxylic acid, 1,2-H 2 BDC = 1,2-benzenedicarboxylic acid, 1,3-H 2 BDC = 1,3-benzenedicarboxylic acid and 1,4-H 2 NDC = 1,4-naphthalenedicarboxylic acid]. Complexes 1−3 based on the same auxiliary ligand show various structures. Complex 1 features a one-dimensional (1D) ∞-like double-chain structure, which consists of a [Cu-1,3,5-HBTC] n chain and [Cu-3-dppa] n meso-helical chain. Complex 2 possesses a (2,4) undulated honeycomb (hcb) net. Complex 3 is a 3-fold interpenetrating three-dimensional (3D) framework, which shows trinodal (2,3,3)-connected topology with the Schlafi symbol of (10•12 2 ) 2 (10 3 ) 2 (12). Complexes 4−6 with 1,2-BDC as secondary ligand exhibit different two-dimensional (2D) layer structures. Complex 4 exhibits a 2D (2,4)-connected (4•12 4 •14)(4) net. Complexes 5 and 6 have similar structures and show 2D networks with undulated sql topology. For complexes 7−10 based on 1,3-BDC secondary ligand, complex 7 shows a 1D zigzag chain, while complexes 8−10 have similar wave-like 2D structures. When 1,4-NDC was used as the auxiliary ligand, complex 11 is a 2D puckered (4,4) network, complex 12 reveals a 4-connected topology with the point symbol of (4 4 •6 2 ), while complex 13 exhibits a 3-fold interpenetrating 3D α-Po framework. The structural diversity indicates that the bis-pyridyl-bis-amide ligands with different spacers and the aromatic polycarboxylates play important roles in tuning the dimensionalities and structures of the title complexes. The fluorescent and photocatalytic properties for 1−13 have also been investigated in detail.

5Metal-organic coordination polymers (MOCPs) are well known organic-inorganic hybrids with infinite structures consisting of metal ions/clusters and organic ligands linked through coordination interactions. MOCPs can be constructed from one or more than one organic bridging ligands (mixed-ligands) and different metal ions. The previous reports prove the fact that the nature of organic ligands and metal ions dominates the final structures as well as properties of the MOCPs in a certain way. Therefore, we focus 10 on discussing the cobalt(II)/copper(II) coordination polymers constructed from the mixed-ligands of polycarboxylates and N-donor ligands, which may possess potential applications in the fields of electrochemistry, electrocatalysis, magnetism and photocatalysis. In this review, we summarize some typical Co(II)/Cu(II) MOCPs based on the mixed bridging organic ligands, aimed to discuss their versatile synthesis methods, topologies and structural influence factors, as well as their tunable properties. 15 All of these aspects are highlighted in this review, which seeks to guide further investigations of cobalt(II)/copper(II) coordination polymers. 65 shown that bis(imidazole)/bis(triazole)/bis(pyridyl) derivatives and polycarboxylate ligands represent the most reliable and typical building blocks which can be jointly applied to synthesize a wide range of desired coordination networks. 13-16 A choice of such connectors in coordination assembly can be rationalized 70 based on the following considerations: (i) the neutral N-donor ligands normally bind to the cobalt(II)/copper(II) ions as the rodlike bidentate tectons; (ii) the polycarboxylate ligands can not