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Bifunctional nanoscale assemblies: multistate electrochromics coupled with charge trapping and release
摘要： We demonstrate controlled charge trapping and release, accompanied by multiple color changes in a metallo-organic bilayer. The dual functionality of the metallo-organic materials provides a fundamental insight into the metal-mediated electron transport pathways. The electrochemical processes are accompanied by distinct, four color–to–color transitions: red, transparent, orange, and brown. The bilayer consists of two elements: (i) a nanoscale gate consisting of a layer of well-defined polypyridyl ruthenium complexes bound to a flexible transparent electrode, and (ii) a charge storage layer consisting of isostructural iron complexes attached to the surface of the gate. This gate mediates or blocks electron transport in response to a voltage. The charge storage and release depend on the oxidation state of the layer of ruthenium complexes (= gate). Combining electrochemistry with optical data revealed mechanistic information: the brown coloration of the bilayer directly relates to the formation of intermediate ruthenium species, providing evidence for catalytic positive charge release mediated through the gate.
关键词： Thin films,Electrochromism,Metallo-organics,Electrochemistry,Charge storage
更新于2025-09-11 14:15:04
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Self‐Assembled Tetrameric Lanthanide‐Containing Germanotungstates [(Ln <sub/>2</sub> GeW <sub/>10</sub> O <sub/>38</sub> ) <sub/>4</sub> (W <sub/>3</sub> O <sub/>8</sub> )(OH) <sub/>4</sub> (H <sub/>2</sub> O) <sub/>2</sub> ] <sup>26?</sup> : Syntheses, Crystal Structure, Photoluminescence and Electrochemical Properties.
摘要： A series of six lanthanide-containing germanotungstates of the formula: [(Ln2GeW10O38)4(W3O8)(OH)4(H2O)2]26? (Ln=Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6) have been synthesized under ambient conditions. The synthetic procedure involves the use of trilacunary Na10[A-α-GeW9O34]?16H2O as a preformed precursor along with lanthanide salts in 0.5 M potassium chloride solution. The interaction of the trilacunary Na10[A-α-GeW9O34]?16H2O with the lanthanide salts leads to the formation of a tetrameric structure with four [GeW10O36]8? dilacunary Keggin units incorporating eight lanthanide ions and three additional tungsten atoms. All the polyanions were structurally characterized by Fourier-transform infrared spectroscopy (FT-IR), Single Crystal X-ray Diffraction (SC-XRD), UV/Visible spectroscopy, thermogravimetric analysis (TGA), electrochemistry, Electron-spray ionization mass spectroscopy (ESI-MS), Powder X-ray diffraction (PXRD) and photoluminescence. FT-IR spectroscopy reveals that all the polyanions are isomorphous and SC-XRD shows that all the polyanions are isostructural and crystalize in the triclinic crystal system with P1 space group. Some of the polyanions show good photoluminescence properties. The cyclic voltammograms (CVs) of all the six compounds exhibit the same shape, each being composed of a pronounced reduction wave.
关键词： Polyoxometalates,Lanthanides,Electrochemistry,Photoluminescence,Germanotungstate
更新于2025-09-11 14:15:04
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The Artificial Leaf: Recent Progress and Remaining Challenges
摘要： The prospect of a device that uses solar energy to split water into H2 and O2 is highly attractive in terms of producing hydrogen as a carbon-neutral fuel. In this mini review, key research milestones that have been reached in this field over the last two decades will be discussed, with special focus on devices that use earth-abundant materials. Finally, the remaining challenges in the development of such “artificial leaves” will be highlighted.
关键词： water splitting,hydrogen production,sustainable hydrogen,artificial photosynthesis,electrochemistry
更新于2025-09-10 09:29:36
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Underpotential co-deposition of ternary Cu-Te-Se semiconductor nanofilm on both flexible and rigid substrates
摘要： To achieve homogeneous ternary compounds, the growth rates of the component species in a solution must be equal and the processes must be simultaneous. The conditions necessary for the growth of one species should not prevent the growth of the others. Herein we present a synthesis of Cu3Te2Se2 semiconductor nanofilms on indium tin oxide (ITO)-coated polyethylene terephthalate (ITO-PET), ITO-coated glass, and Au plate substrates by an electrochemical underpotential co-deposition (UPCD) method from the same solution at a constant potential. The chemical, morphological, and optical properties of the synthesized nanofilms were determined by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, ultraviolet-visible absorption spectroscopy (UV/Vis), and current-voltage (I-V) studies. The chemical formula of the deposited nanofilms was confirmed as Cu3Te2Se2 by X-ray photoelectron spectroscopy. The SEM images exhibited uniform nano-scale (~40 nm) distribution of the Cu3Te2Se2 nanofilms. The band gaps of the deposited films were determined according to the different deposition times and potentials. The XRD results showed crystalline and single-phase forms of Cu3Te2Se2 nanofilm. Finally, the I-V curves of the Cu3Te2Se2/ITO heterojunctions at room temperature (RT) under normal light conditions indicated matched those of a diode model.
关键词： Ternary Cu-Te-Se,Diode,Underpotential Co-deposition,Flexible surface,Electrochemistry,Semiconductor
更新于2025-09-10 09:29:36
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A family of solution processable ligands and their Re(I) complexes towards light emitting applications
摘要： A series of trimine ligands incorporating 2,2′:6′,2′′-terpyridine (terpy), 2,6-di(thiazol-2-yl)pyridine (dtpy), and 2,6-di(pyrazin-2-yl)pyridine (dppy) frameworks, as well as their corresponding Re(I) tricarbonyl complexes were successfully designed and synthesized to investigate the impact of the peripheral rings (pyridine, thiazole and pyrazine) and phenyl– or naphthyl–based substituents attached to the triimine skeleton on their photophysical and electroluminescent properties. The experimental studies were accompanied with DFT/TDDFT calculations. DSC investigations showed that both the free ligands and Re(I) complexes melted at high temperature (164–309oC) and some of them are able to form amorphous materials. CV measurements revealed that energy band gaps calculated on the basis of ionization potential and electron affinity of the Re(I) complexes, which are correlated with energy levels of frontier molecular orbitals, fall in the range of 2.14–2.32 eV, being lower than the corresponding ligands, what makes the complexes promising for organoelectronic applications. The photophysical properties of the synthesized triimine ligands and Re(I) complexes were studied in detail by electronic absorption and emission. In solution they exhibited photoluminescence quantum yields ranging from 0.15% to 84.42% depending on the chemical structure. The presence of pyrazine units significantly reduced ability for radiative emission. All the compounds were emissive also in a solid state. Preliminary tests of electroluminescence ability demonstrated that most of the devices with Re(I) complexes exhibited red or orange emission, while diodes with ligands showed maximum of emission band located mainly in the green region. It should be noticed that diodes with active layer consisting of a neat complex (ITO:PEDOT:PSS/complex/Al) emitted light under applied voltage.
关键词： electroluminescence,photoluminescence,electrochemistry,Re(I) complexes,triimine ligands
更新于2025-09-10 09:29:36
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Tracing the Origin of Visible Light Enhanced Oxygen Evolution Reaction
摘要： Hybrid nanostructures with a plasmonic core and catalytic shell often show significantly enhanced catalytic efficiency under illumination of specific frequency. Excitation of localized surface plasmonic resonance on plasmonic metals under illumination can generate hot electrons that assist in the catalytic reaction. However, the correlation between the microstructural geometry, dielectric environment, internal energy flow in the hybrid structure, and the chemical reaction rate is so far not clear. Here, a composite with a plasmonic Au metal yolk and a nearly transparent Ni3S2 shell is designed to maximize the absorption of incident light by forming strong localized surface plasmonic resonance at the yolk as predicted by 3D finite element method. The incoming photoenergy is dominantly dissipated on the shell by forming electron–hole pairs, leading to higher energy flow rate for oxygen evolution reaction. The overpotential is 252 mV at 10 mA cm?2 and the catalytic activity of Au@Ni3S2 achieves ca. 85-fold that of pure Ni3S2 under illumination and surpasses the commercial IrO2 catalyst. The study opens the door of exploration of highly effective hybrid composite catalysts for energy applications.
关键词： gold,localized surface plasmonic resonance (LSPR),nickel,photo-electrochemistry,electrocatalysts
更新于2025-09-10 09:29:36
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Near-Infrared Photoluminescence and Electrochemiluminescence from a Remarkably Simple Boron Difluoride Formazanate Dye
摘要： Electrochemiluminescence involves the generation of light via electrochemical reactions and has recently shown utility for single-cell imaging. To further develop this novel imaging platform, it is necessary to produce readily available dyes that photoluminesce and electrochemiluminesce in the near-infrared region to limit absorption by biological tissue. To address this need, we prepared a boron difluoride formazanate dye that exhibits near-infrared photoluminescence in two straightforward synthetic steps. Examination of its solid-state structure suggests that the N-aryl substituents have significant quinoidal character, which narrows the S1-S0 energy gap and leads to near-infrared absorption and photoluminescence. Electrochemical properties were probed using cyclic voltammetry and revealed four electrochemically reversible waves. Electrochemiluminescence properties were examined in the presence of tri-n-propylamine, leading to maximum intensity at 910 nm, at least 85 nm (1132 cm?1) red-shifted compared to all other organic dyes. This work sets the stage for the development of future generations of dyes for emerging applications, including single-cell imaging, that require near-infrared photoluminescence and electrochemiluminescence.
关键词： NIR electrochemiluminescence,Electrochemistry,Formazanate ligands,Organic dyes,NIR photoluminescence
更新于2025-09-10 09:29:36
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11.2: <i>Invited Paper:</i> Electrochromics for Full Color e-Paper and Energy-Saving Application
摘要： Novel multicolor electrochromic (EC) device based on electrochemical silver deposition was successfully demonstrated. The EC device exhibited reversible multicolor change of primary colors― transparent, magenta, cyan, yellow, black (CMYK) and silver mirror ―in a single cell by using electrochemical method which controlled the morphology of silver deposit.
关键词： Silver electrodeposition,Electrochromism,Localized surface plasmon resonance,Electrochemistry,Multicolor
更新于2025-09-10 09:29:36
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Electrochemistry of zinc tetraarylporphyrins containing fused butano and benzo groups. Effect of solvent and substituents on spectra, potentials and mechanism in nonaqueous media
摘要： Two series of zinc tetraarylporphyrins containing four b,b′-pyrrole fused butano or benzo groups were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in nonaqueous media. The examined compounds are represented as butano(Ar)4PorZn and benzo(Ar)4PorZn, where Por is the porphyrin dianion and Ar is a p-CH3Ph, Ph or p-ClPh substitutent on meso-positions of the macrocycle. Each Zn(II) butano- and benzoporphyrin undergoes two one-electron reductions to give a p-anion radical and dianion in CH2Cl2. In contrast, three reductions were observed for the benzoporphyrin derivatives in pyridine, the third of which is assigned as electron addition to a benzophlorin anion generated from the doubly reduced benzoporphyrin. Two overlapped one-electron oxidations were observed for the butanoporphyrins in CH2Cl2, a result not previously observed for any other zinc porphyrin. The electrochemically measured HOMO–LUMO gap of the benzoporphyrins ranges from 1.89 to 1.90 V in CH2Cl2 and from 1.93 to 1.95 V in pyridine. Both values are smaller than the gaps of butanoporphyrins at 2.11–2.13 V in CH2Cl2 and 2.07–2.09 V in pyridine.
关键词： spectroelectrochemistry,electrochemistry,substituent effect,synthesis,porphyrinoids
更新于2025-09-10 09:29:36
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Wireless Addressing of Free-Standing MoSe2 Macro- and Microparticles by Bipolar Electrochemistry
摘要： Doping of a transition metal dichalcogenide deposited onto a conducting surface acting as bipolar electrode was recently reported. Here, free-standing macro- and microscale transition metal dichalcogenide substrates are successfully employed as effective bipolar electrodes without the need of using an additional conducting support. This is first demonstrated by achieving site-selective bipolar electrodeposition of several metals such as gold, silver, copper and nickel on macroscale MoSe2 substrates (typically 1 cm in size). Also, the superior efficiency of MoSe2 compared to a carbon substrate towards hydrogen evolution reaction, well-known in conventional electrochemistry, is demonstrated in the bipolar electrochemistry configuration. Such electrocatalytic properties can be advantageously used by combining this reduction with a given oxidation reaction in order to ease the electrochemical coupling. Also, as a wireless technique, bipolar electrochemistry enables the simultaneous addressing of large ensembles of bipolar electrodes with a single pair of driving electrodes. Therefore, in a bulk experiment, a suspension composed of thousands of individual MoSe2 microparticles (with a typical size of 20-80 μm) that are addressed simultaneously, is employed to significantly accelerate an electrolysis. Amplex? Red was selected as an oxidizable organic model dye. Such an electrolysis occurs on the timescale of several seconds which is definitely not achievable by addressing a single macroscale MoSe2 bipolar electrode. This performance is due to the collective behavior of the ensemble of MoSe2 bipolar electrodes because the oxidation process occurs simultaneously at each individual anodic pole.
关键词： electrodeposition,MoSe2,bipolar electrochemistry,transition metal dichalcogenide,hydrogen evolution reaction
更新于2025-09-10 09:29:36