scholarly journals Reductive Electropolymerization and Electrochromism of Iron(II) Complex with Styrene-Based Ligand

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4831
Author(s):  
Sergiusz Napierała ◽  
Kacper Muras ◽  
Grzegorz Dutkiewicz ◽  
Monika Wałęsa-Chorab
Keyword(s):  
Cyclic Voltammetry ◽  
Absorption Band ◽  
Thin Layer ◽  
Reduction Process ◽  
Redox Processes ◽  
Polymeric Complex ◽  
Color Changes ◽  
Oxidation Reduction ◽  
Reversible Redox ◽  
The Stability

The benzimidazole-based ligand containing polymerizable styrene group has been prepared via condensation of picolinaldehyde derivative containing styrene moiety and benzimidazole-based hydrazine. The ligand reacted with iron(II) tetrafluoroborate and iron(II) trifluoromethanesulfonate giving red-brown complexes of Fe(II) ions of formula [FeL2]X2, where X = CF3SO3− (1) or BF4− (2). Reductive electropolymerization was used to obtain a thin layer of the polymeric complex, poly-1. Further investigation of electrochemical properties of the compound by cyclic voltammetry showed two quasi-reversible redox processes assigned to electrooxidation and electroreduction of the polymer. Spectroelectrochemical measurements confirmed that the polymer undergoes the color changes during oxidation and reduction process. The polymer in its neutral state (Fe(II)) is yellow and it exhibits absorption band at 370 nm, after oxidation to Fe(III) state absorption band shifts to 350 nm and the polymer is almost colorless. While the metal ions are reduced to Fe(I) absorption band at around 410 nm has been observed and the polymer changed its color to intense yellow. The stability of the polymer during multiple oxidation/reduction cycles has also been investigated.

Unusual Wetting Behavior of Liquid Metals on Porous Layer Formed at Surface of Iron Substrate Prepared by Oxidation-Reduction Process

2007 ◽  
Vol 561-565 ◽  
pp. 1699-1701
Author(s):  
Nobuyuki Takahira ◽  
Takeshi Yoshikawa ◽  
Toshihiro Tanaka
Keyword(s):  
Liquid Metal ◽  
Porous Layer ◽  
Liquid Metals ◽  
Reduction Process ◽  
Surface Oxidation ◽  
Porous Iron ◽  
Normal Contact ◽  
Wetting Behavior ◽  
Oxidation Reduction ◽  
Oxidized Iron

Unusual wetting behavior of liquid Cu was found on a surface-oxidized iron substrate in reducing atmosphere. Liquid Cu wetted and spread very widely on the iron substrate when a droplet was attached with the substrate in Ar-10%H2 after the surface oxidation of the substrate. The oxidationreduction process fabricates a porous layer at the surface of the iron substrate. The pores in the porous iron layer are 3-dimensionally interconnected. Thus, liquid metals, which are contacted with the reduced iron samples, penetrate into these pores by capillary force to cause the unusual wetting behavior. It has been already confirmed that liquid Ag, Sn, In and Bi show this phenomenon onto surface-porous iron samples as well as liquid Cu. This unusual wetting behavior of a liquid metal has been correlated to the normal contact angle of the liquid metal on a flat iron substrate.

Performance of poly-o-phenylenediamine and its carbon dot composite electrode in the removal of Cu2+ from its aqueous solution

2021 ◽  
pp. 2151037
Author(s):  
Yu Meng ◽  
Qing Zhong ◽  
Arzugul Muslim
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Reduction ◽  
Composite Electrode ◽  
Reduction Process ◽  
Order Kinetic ◽  
Carbon Dot ◽  
First Order ◽  
Oxidation Reduction ◽  
Order Kinetic Model ◽  
Optimal Ph

Because −NH2 and −NH− in poly-[Formula: see text]-phenylenediamine (P[Formula: see text]PD) can interact strongly with the empty orbitals of Cu to show unique electrochemical activity, P[Formula: see text]PD is suitable for the removal of Cu[Formula: see text] by electrochemical oxidation–reduction process. In this study, with P[Formula: see text]PD and its carbon dot composite (CDs/P[Formula: see text]PD) as working electrodes, the electrochemical reduction and removal of Cu[Formula: see text] in the aqueous solution were carried out with the potentiostatic method. According to effects of voltage, pH of the solution, initial concentration of Cu[Formula: see text], and electrochemical reduction time on the Cu[Formula: see text] removal, the Cu[Formula: see text] removal ratios of P[Formula: see text]PD and CDs/P[Formula: see text]PD were up to 64.69% and 73.34%, respectively, at −0.2 V and the optimal pH. Additionally, results showed that these processes were in line with the quasi-first order kinetic model. Both P[Formula: see text]PD and CDs/P[Formula: see text]PD showed good reproducibility in six cycles. After five times of repeated usage, the regeneration efficiencies of P[Formula: see text]PD and CDs/P[Formula: see text]PD dropped to 77.04% and 79.36%, respectively.

scholarly journals Alternating copolymerization of cyclic germylenes with N-phenyl-p-quinoneimine via oxidation-reduction process

2016 ◽  
Vol 48 (9) ◽  
pp. 969-972
Author(s):  
Hiroshi Takano ◽  
Masafumi Hiraishi ◽  
Shigeru Yaguchi ◽  
Satoru Iwata ◽  
Shin-ichiro Shoda ◽  
...  
Keyword(s):  
Reduction Process ◽  
Oxidation Reduction ◽  
Alternating Copolymerization

Fundamental and Technological Aspects of Actinide Oxide Pyrochlores: Relevance For Immobilization Matrices

1999 ◽  
Vol 556 ◽  
Author(s):  
P. E. Raison ◽  
R. G. Haire ◽  
T. Sato ◽  
T. Ogawa
Keyword(s):  
Elevated Temperatures ◽  
Materials Science ◽  
Oxidation Potential ◽  
Oxygen Stoichiometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxidation Reduction ◽  
Reduction Cycle ◽  
Fluorite Type ◽  
The Stability

AbstractPolycrystalline pyrochlore oxides consisting of selected f elements (lanthanides and actinides) and Zr and Hf have been prepared and characterized. Characterization to date has been primarily by X-ray diffraction, both at room and at elevated temperatures. Initial studies concentrated on selected lanthanides and the Np, Pu and Am analogs (reported here) but have been extended to the other actinide elements through Cf. Data from these studies have been used to establish a systematic correlation regarding the fundamental materials science of these particular pyrochlores and structurally related fluorite-type dioxides. In addition to pursuing their materials science, we have addressed some potential technological applications for these materials. Some of the latter concern: (1) immobilization matrices; (2) materials for transmutation concepts; and (3) special nuclear fuel forms that can minimize the generation of nuclear wastes. For f elements that display both a III and IV oxidation state in oxide matrices, the synthetic path required for producing the desired pyrochlore oxide is dictated by their pseudo-oxidation potential the stability of the compound towards oxygen uptake. For the f elements that display an oxidationreduction cycle for pyrochlore-dioxide solid solution, X-ray diffraction can be used to identify the composition in the oxidation-reduction cycle, the oxygen stoichiometry and/or the composition. This paper concentrates on the Np, Pu and Am systems, and addresses the above aspects, the role of the crystal matrix in controlling the ceramic products as well as discussingsome custom-tailored materials.

scholarly journals Redox Property Tuning in Bipyridinium Salts

2021 ◽  
Vol 8 ◽  
Author(s):  
Zuzana Burešová ◽  
Milan Klikar ◽  
Petr Mazúr ◽  
Michaela Mikešová ◽  
Jaroslav Kvíčala ◽  
...  
Keyword(s):  
Redox Processes ◽  
Rotating Disc Electrode ◽  
Structure Property ◽  
Disc Electrode ◽  
Rotating Disc ◽  
Half Cell ◽  
Redox Flow Batteries ◽  
Structure Property Relationships ◽  
Reversible Redox ◽  
Small Capacity

Bipyridinium salts are currently very popular due to their perspective applications in redox flow batteries. Hence, we designed and prepared a series of bipyridiniums based on 2,2′-, 3,3′-, and 4,4′-bipyridine and 2,2′-bipyrimidine. The straightforward synthesis utilizes commercially or readily available starting compounds and their direct N-alkylation, mostly using 1,3-propanesultone. All eleven target derivatives with systematically evolved structure were investigated by cyclic voltammetry, which allowed elucidating thorough structure-property relationships. The electrochemical behavior depends primarily on the parent scaffold, type of N-alkylation, number of quaternized nitrogen atoms, planarity, counter ion as well as the used media. Two derivatives featuring quasi-reversible redox processes were further tested on rotating disc electrode and in a flow battery half-cell. 4,4′-Bipyridinium derivative bearing two sultone residues showed better performance and stability in the flow half-cell with small capacity decays of 0.09/0.15% per reduction-oxidation cycle, based on the number of the utilized redox processes (one/two).

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