Publications by authors named "Mjejri I"

Article Synopsis
  • Mixing silver nanowires (AgNWs) into PEDOT:PSS films significantly improves conductivity, reducing sheet resistance from 280 Ω/sq to 34 Ω/sq.
  • The addition also enhances electrochromic performance by lowering the turn-on voltage from -1.5 V to -1.1 V and speeding up switching time from 7 to 3.6 seconds.
  • This method eliminates the need for costly and environmentally harmful ITO electrodes, making hybrid AgNW/PEDOT:PSS devices more efficient and effective overall.
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Due to their remarkable properties, including remarkable porosity and extensive surface area, metal-organic frameworks (MOFs) are being investigated for various applications. Herein, we report the first Co(II)-based mixed ligand MOF, formulated Co(HTrz)(d-cam)(μ-OH). Its 3D structure framework is composed of helical chains {[Co(μ-HTrz)]} connected by d-camphorate ligand building blocks and featured as an extended structure in an AB-AB fashion.

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A novel semiconducting Ni(II)-based hybrid material with the formula (CHN) NiCl, which exhibits interesting optical and electrical properties, is reported. The crystal structure was investigated using SCXRD, whereas physical properties were studied by means of thermal analysis, Ft-Infrared, optical, and electrical measurements. Its crystal packing is formed through organic rings surrounded by inorganic [NiCl] tetrahedral and stacked along the -crystallographic axis.

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Article Synopsis
  • Electrochromism is the ability of materials to change their optical properties when a voltage is applied, and it has many practical applications, though vanadium dioxide (VO) has been less explored for this purpose.
  • This study reveals that thick films of VO can exhibit multiple color changes, shifting from orange to green and blue when cycled in a lithium-based electrolyte, due to a process of amorphization and recrystallization.
  • The observed color changes are linked to VO's oxidation and reduction states, showcasing a strong memory effect that allows for the detailed tracking of the coloration mechanisms involved.
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Poly(3,4-ethylenedi-oxythiophene) (PEDOT) derivatives conducting polymers are known for their great electrochromic (EC) properties offering a reversible blue switch under an applied voltage. Characterizations of symmetrical EC devices, built on combinations of PEDOT thin films, deposited with a bar coater from commercial inks, and separated by a lithium-based ionic membrane, show highest performance for 800 nm thickness. Tuning of the color is further achieved by mixing the PEDOT film with oxides.

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Devices displaying controllably tunable optical properties through an applied voltage are attractive for smart glass, mirrors, and displays. Electrochromic material development aims to decrease power consumption while increasing the variety of attainable colors, their brilliance, and their longevity. We report the first electrochromic device constructed from metal organic frameworks (MOFs).

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In this study, vanadium sesquioxide (VO), dioxide (VO), and pentoxide (VO) were all synthesized from a single polyol route through the precipitation of an intermediate precursor: vanadium ethylene glycolate (VEG). Various annealing treatments of the VEG precursor, under controlled atmosphere and temperature, led to the successful synthesis of the three pure oxides, with sub-micrometer crystallite size. To the best of our knowledge, the synthesis of the three oxides VO, VO, and VO from a single polyol batch has never been reported in the literature.

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Herein, the successful synthesis of Ti-doped vanadium pentoxide from a polyol process is reported. A high Ti concentration (up to 8.5 mol % of the total metallic content) can be inserted in vanadium oxide thanks to the synthesis route leading to nanometric crystallites.

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Hierarchically structured nano-vanadium oxides with different morphologies have been synthesized via a template-free hydrothermal route by adjusting the organic precursor quantities. The effects of molar ratio on structure, morphology and crystallite sized were investigated. The possible growth mechanism is also proposed.

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