Search results for "electrochemical cell"
showing 10 items of 104 documents
Deep-Red-Emitting Electrochemical Cells Based on Heteroleptic Bis-chelated Ruthenium(II) Complexes
2009
Two ruthenium(II)-based complexes were prepared that show intense deep-red light emission at room temperature. Solid-state electroluminescent devices were prepared using one of the ruthenium complexes as the only active component. These devices emit deep-red light at low voltages and exhibit extraordinary stabilities, demonstrating their potential for low-cost deep-red light sources.
Chloride ion impact on materials for light-emitting electrochemical cells
2013
Small quantities of Cl(-) ions result in dramatic reductions in the performance of ionic transition metal complexes in light-emitting electrochemical cells. Strong ion-pairing between aromatic protons and chloride has been established in both the solid state and solution. X-ray structural determination of 2{[Ir(ppy)2(bpy)][Cl]}·2CH2Cl2·[H3O]·Cl reveals the unusual nature of an impurity encountered in the preparation of [Ir(ppy)2(bpy)][PF6].
Observation of electroluminescence at room temperature from a ruthenium(II) bis-terpyridine complex and its use for preparing light-emitting electroc…
2005
A terpyridine ruthenium (II) complex containing a substituted and an unsubstituted terpyridine ligand was synthesized, and its luminescence properties were studied in a solid-state single-layer light-emitting electrochemical cell. The obtained devices emitted light of a very deep red color (CIE, x = 0.717 y = 0.282) at low external applied bias. It is the first example of an electroluminescence device based on a bis-chelated ruthenium complex. Its ambient atmosphere decay is remarkably different from analogous devices using tris-chelated ruthenium complexes.
A comparative study of Ir(III) complexes with pyrazino[2,3-f][1,10]phenanthroline and pyrazino[2,3-f][4,7]phenanthroline ligands in light-emitting el…
2015
We report the comparative study of the electrochemical and photoluminescent properties of two Ir(iii) complexes described as [Ir(F2ppy)2(N^N)][PF6], where the F2ppy ligand is 2-(2,4-difluorophenyl)pyridine and the N^N ligands are pyrazino[2,3-f][1,10]phenanthroline (ppl) and pyrazino[2,3-f][4,7]phenanthroline (ppz). The complexes were used for the fabrication of light-emitting electrochemical cells (LECs). The structures of the complexes have been corroborated by X-ray crystallography. Theoretical calculations were performed to understand the photophysical behavior of the complexes. Both in solution and solid state, the photoluminescence spectra shows that emission is significantly red-shif…
Luminescent Ionic Transition-Metal Complexes for Light-Emitting Electrochemical Cells
2012
Higher efficiency in the end-use of energy requires substantial progress in lighting concepts. All the technologies under development are based on solid-state electroluminescent materials and belong to the general area of solid-state lighting (SSL). The two main technologies being developed in SSL are light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs), but in recent years, light-emitting electrochemical cells (LECs) have emerged as an alternative option. The luminescent materials in LECs are either luminescent polymers together with ionic salts or ionic species, such as ionic transition-metal complexes (iTMCs). Cyclometalated complexes of Ir(III) are by far the most util…
Highly Stable Red-Light-Emitting Electrochemical Cells
2017
The synthesis and characterization of a series of new cyclometalated iridium(III) complexes [Ir(ppy) 2 (N ∧ N)][PF 6 ] in which Hppy = 2-phenylpyridine and N ∧ N is (pyridin-2-yl)benzo[ d ]thiazole ( L1 ), 2-(4-( tert -butyl)pyridin-2-yl)benzo[ d ]thiazole ( L2 ), 2-(6-phenylpyridin-2-yl)benzo[ d ]thiazole ( L3 ), 2-(4-( tert -butyl)-6-phenylpyridin-2-yl)benzo[ d ]thiazole ( L4 ), 2,6-bis(benzo[ d ]thiazol-2-yl)pyridine ( L5 ), 2-(pyridin-2-yl)benzo[ d ]oxazole ( L6 ), or 2,2′-dibenzo[ d ]thiazole ( L7 ) are reported. The single crystal structures of [Ir(ppy) 2 ( L1 )][PF 6 ]·1.5CH 2 Cl 2 , [Ir(ppy) 2 ( L6 )][PF 6 ]·CH 2 Cl 2 , and [Ir(ppy) 2 ( L7 )][PF 6 ] have been determined. The new com…
Online Visualization of Corrosion Processes of Zinc and a Cu/Zn Galvanic Pair in Lithium Bromide Solutions
2003
Abstract A new method has been developed for online visualization of corrosion processes. The system allows surface images of the tested electrode to be captured simultaneously with the recorded electrochemical signal caused by corrosion processes without disturbing the electrochemical system. The experimental device consists of an electrochemical system with a horizontal electrochemical cell coupled to optical equipment. The horizontal position of the electrodes tested permitted the direct observation of surface modifications with time and of the experimental conditions by means of a triocular microscope stereoscope assembled to an image acquisition system. The new methodology was applied …
Multipore membranes with nanofluidic diodes allowing multifunctional rectification and logical responses
2016
[EN] We have arranged two multipore membranes with conical nanopores in a three-compartment electrochemical cell. The membranes act as tunable nanofluidic diodes whose functionality is entirely based on the pH-reversed ion current rectification and does not require specific surface functionalizations. This electrochemical arrangement can display different electrical behaviors (quasi-linear ohmic response and inward/outward rectifications) as a function of the electrolyte concentration in the external solutions and the applied voltage at the pore tips. The multifunctional response permits to implement different logical responses including NOR and INHIBIT functions.
Nanostructured electrodes for hydrogen production in alkaline electrolyzer
2018
Abstract Ever-widespread employment of renewable energy sources, such as wind and sun, request the simultaneous use of effective energy storage systems owing to the intermittent and unpredictable energy generation by these sources. The most reliable storage systems currently under investigation are batteries and electrochemical cells for hydrogen production from water splitting. Both systems store chemical energy which can be converted on demand. The low power density is the weakness of the batteries while the high production cost limits currently the wide use of hydrogen from electrochemical water splitting. In this work, attention was focused on the use of nanostructured Ni as a cathode f…
Dismantling and electrochemical copper recovery from Waste Printed Circuit Boards in H2SO4–CuSO4–NaCl solutions
2019
Abstract The worldwide growing of electrical and electronic equipment makes increasingly urgent to find environmentally friendly treatments for e-waste. In this paper, the attention has been focused on i) the eco-friendly dismantling of the electronic components from Waste Printed Circuit Boards and ii) recovering of pure metallic copper, which is the most abundant metal and one of the most valuable in Printed Circuit Boards. After an experimental optimization study, we found that a solution containing 0.5 M H2SO4, 0.4 M CuSO4, and 4 M NaCl can be successfully used to disassemble the electronic components from the boards by leaching of all exposed metals. Air was blown into the leaching sol…