Porous conjugated polymer nanotip arrays for highly stable field emitter

A bipolar-redox tetraalkynylporphyrin macrocycle positive electrode with 12-electrons-transfer for high-energy aluminum-organic batteries

Organic electrode materials with bipolar-redox activity are a promising candidate for high-energy aluminum-ion batteries (AIBs), but face the capacity ceiling due to limited active sites and low electron transfer number. To universally address this issue, seeking for a kind of multisite bipolar organic material to achieve multielectron transfer is a prerequisite but challenging. Herein, we develop a 12-electron transfer tetraalkynylporphyrin macrocycle positive electrode with two p-type amine (‒NH‒) motifs, two n-type imine (C = N) motifs and four n-type alkynyl (C ≡ C) motifs. The bipolar 18π-electron porphyrin macrocycle can alternately bind and release AlCl4- anions at ‒NH‒ sites and AlCl2+ cations at C = N sites (oxidized from 18π to 16π or reduced from 18π to 20π), achieving four electrons transfer. Furthermore, each terminal C ≡ C site can also coordinate with two AlCl2+ cations, thereby delivering eight electrons. The designed aluminum-organic battery achieves a high capacity of up to 347 mAh g-1 (3-6 times that of conventional graphite positive electrode, 60-120 mAh g-1) and a high specific energy of 312 Wh kg-1 (up to 150% compared to cells with graphite as positive electrode) based on the mass of positive electrode materials.

Preparation of a Sulfur-Functionalized Microporous Polymer Sponge and In Situ Growth of Silver Nanoparticles: A Compressible Monolithic Catalyst

We report a compressible monolithic catalyst based on a microporous organic polymer (MOP) sponge. The monolithic MOP sponge was synthesized via Sonogashira-Hagihara coupling reaction between 1,4-diiodotetrafluorobenzene and 1,3,5-triethynylbenzene in a cosolvent of toluene and TEA (2:1, v/v) without stirring. The MOP sponge had an intriguing microstructure, where tubular polymer fibers having a diameter of hundreds of nanometers were entangled. It showed hierarchical porosity with a Brunauer-Emmett-Teller (BET) surface area of 512 m² g^-1. The MOP sponge was functionalized with sulfur groups by the thiol-yne reaction. The functionalized MOP sponge exhibited a higher BET surface area than the MOP sponge by 13% due to the increase in the total pore and micropore volumes. A MOP sponge-Ag heterogeneous catalyst (S-MOPS-Ag) was prepared by in situ growth of silver nanoparticles inside the sulfur-functionalized MOP sponge by the reduction of Ag⁺ ions. The catalytic activity of S-MOPS-Ag was investigated for the reduction reaction of 4-nitrophenol in an aqueous condition. When S-MOPS-Ag was compressed and released during the reaction, the rate of the reaction was considerably increased. S-MOPS-Ag was easily removed from the reaction mixture owing to its monolithic character and was reused after washing and drying.

Mixed Phthalocyanine-Porphyrin Fused Conjugated Pentameric Nanoarrays

The largest phthalocyanine-porphyrin-fused pentameric molecular arrays have been synthesized and spectroscopically characterized. The saddled molecular conformation revealed for the pentamer by DFT-D3 calculation in combination with the bulky peripheral substituents precludes effective face-to-face π-π intermolecular interaction. As a consequence, intermolecular C-H⋅⋅⋅π interactions together with the ubiquitous dispersion force arrays help to self-assemble the representative metal-free pentameric molecules into the three-dimensional supramolecular structures with nanorod morphology in CHCl₃ and n-butanol. Powder X-ray diffraction (XRD) analysis and selected area electron diffraction (SAED) disclose the gradually increased long range of molecular ordering in the nanorods along with the increase in the substrate temperature from 30, 40, 50, to 60 °C. This in turn results in an increase in the semiconductivity of the single nanorod in the same order from 9.4×10^-9 to 3.8×10^-8 , 7.6×10^-7 , and 6.3×10^-5  S m^-1 .

High Conductive Two-Dimensional Covalent Organic Framework for Lithium Storage with Large Capacity

A high conductive 2D COF polyporphyrin (TThPP) linked by 4-thiophenephenyl groups was synthesized through an in situ chemical oxidative polymerization on the surface of copper foil. The TThPP films were used as the anode of lithium-ion battery, which exhibited high specific capacities, excellent rate performances, and long cycle lives due to the alignment of 2D polyporphyrin nanosheets, and they (i) can highly efficiently adsorb Li atoms, (ii) have short-ended paths for the fast lithium ion diffusion, and (iii) open nanopores holding electrolyte. The reversible capacity is up to 666 mAh/g. This is the first example of an organic 2D COF for an anode of lithium-ion battery and represents an important step toward the use of COFs in the next-generation high-performance lithium-ion battery.

Electrochemical fabrication of one-dimensional porphyrinic wires on electrodes

[5,15-Di(4-aminophenyl)-10,20-diphenylporphyrinato]zinc(ii) was found to electropolymerize on electrodes such as glassy carbon (GC), indium tin oxide (ITO), and tin oxide, to form a redox-active, stable, and reproducible π-conjugated polymer.

Microporous polymer network films covalently bound to gold electrodes

Covalent attachment of a microporous polymer network (MPN) on a gold surface is presented. A functional bromophenyl-based self-assembled monolayer (SAM) formed on the gold surface acts as co-monomer in the polymerisation of the MPN yielding homogeneous and robust coatings. Covalent binding of the films to the electrode is confirmed by SEIRAS measurements.

Self-assembly of functional molecules into 1D crystalline nanostructures

Self-assembled functional nanoarchitectures are employed as important nanoscale building blocks for advanced materials and smart miniature devices to fulfill the increasing needs of high materials usage efficiency, low energy consumption, and high-performance devices. One-dimensional (1D) crystalline nanostructures, especially molecule-composed crystalline nanostructures, attract significant attention due to their fascinating infusion structure and functionality which enables the easy tailoring of organic molecules with excellent carrier mobility and crystal stability. In this review, we discuss the recent progress of 1D crystalline self-assembled nanostructures of functional molecules, which include both a small molecule-derived and a polymer-based crystalline nanostructure. The basic principles of the molecular structure design and the process engineering of 1D crystalline nanostructures are also discussed. The molecular building blocks, self-assembly structures, and their applications in optical, electrical, and photoelectrical devices are overviewed and we give a brief outlook on crucial issues that need to be addressed in future research endeavors.

Experimental and theoretical investigation of enhanced cold cathode emission by plasma-etched 3d array of nanotips derived from CuPc nanotube

Experimentally observed field emission responses of 3D copper phthalocyanine (CuPc) nanotip arrays synthesized over nanotube walls by facile plasma treatment and theoretical justifications via finite element method based simulations.

Efficient and persistent cold cathode emission from CuPc nanotubes: a joint experimental and simulation investigation

Experimentally observed excellent cold cathode emission characteristics of chemically synthesized CuPc nanotubes and theoretical justifications via finite element method simulation.