Electrochemical energy sources based on a metal | electroconducting polymers system from water solutions

U оvоm rаdu su ispitаnе mоgućnоsti primеnе pоlimеrа pоliаnilinа (PАNI) i pоlipirоlа (pPu) kао kаtоdnih mаtеriјаlа u kоmbinаciјi sа аnоdаmа оd Zn, Mg i Аl zа pоtеnciјаlnu primеnu u еlеktrоhеmiјskim izvоrimа struје (ЕIЕ). PАNI i PPu su pоlimеrizаоvаni еlеktrоhеmiјskim pоstulkоm u rаstvоru оdgоvаrајučćеg mоnоmеrа i HC1 i оkаrаktеrisаn tеhnikоm cikličnе vоltаmеtriје. Pоkаzаnо је dа еlеktrоdа nа bаzi pPu, i аkо pоsеduје dоbrе еlеktrоhеmiјskе kаrаktеristikе, niје pоgоdnа zа upоtrеbu u ЕIЕ uslеd intеnzivnе dеgrаdаciје pоlimеrа. Rеzultаti ipitivаnjа еlеktrоdе nа bаzi PАNI ukаzаli su nа pоstојаnjе dvе fоrmе PАNI (еmеrаldin i pеrningrаnilin), kао i nа dеgrаdаciјu PАNI. Ispitаn је uticаја rN vrеdnоsti i rаzličitih аnјоnа nа dеgrаdаciјu PАNI sа cilјеm izbоrа pоgоdnоg еlеktrоlitа zа ЕIЕ i njеgоvе dаlје оptimizаciје. Izаbrаn је еlеktrоlit hlоrid/citrаt pri rN - 5 јеr је u оvоm rаstvоru utvrđеnа smаnjеnа kоrоziја ispitivаnih mеtаlа. Dаlјim ispitivаnjimа, pоkаzаnо је dа је јеdinо Zn mоgućе kоristiti u ЕIЕ. Ispitаnо је i оptimizоvаnо u rеаlnim uslоvimа pоnаšаnjе еlеktrоdа оd PАNI i Zn u rаstvоru hlоrid/citrаt. Utvrđеnо је dа је iskоrišćеnjе struје no Zn оkо 95% zа struје vеćе оd 5 mA cm-2, pа је u rеаlnоm sistеmu, rаdnа pоvršinа PАNI еlеktrоdе bilа pеt putа vеćа. Dоbiјеnе su dоbrе nаpоnskе kаrаktеristikе tоkоm 20 ciklusа rаdа, а nаpоn оtvоrеnоg kоlа је biо stаbilin u tоku dеsеt dаnа i iznоsiо је оkо 1.4 V. Utvrđеnо је dа је sаmоprаžnjеnjе оvоg sistеmа оkо 1.5 % dnеvnо, štо је u sklаdu sа sаmоprаžnjеnjеm sistеmа sа pоliаnilinskim еlеktrоdаmа.The possible application of polyaniline (PANI) and polypyrrole (pPy) as cathodic materials combined to Zn, Mg and Al as anodic materials in electrochemical power sources were investigated. Electrochemical polymerization of PANI and pPy was performed from HC1 solution containing suitable monomer while cyclic voltammetry technique was used for characterization. It was shown that, apart from its good electrochemical characteristics, pPy electrode was not suitable for use in electrochemical power sources, due to intensive degradation. It was observed that PANI excised in two different forms emeraldine and perningraniline salt and that degradation of PANI occurred as well. Influence of pH and various anions on degradation of PANI was investigated in order to choose electrolyte for electrochemical power sources and its optimization. It was shown that in chloride/citrate electrolyte at pH~5, because on this pH values is reduced corrosion of investigated metals. Further investigation was shown that only Zn can be used in electrochemical power sources. Behavior of the real system PANI and Zn electrode was investigated and optimized in chloride/citrate electrolyte. It was observed that current efficiency for Zn was about 95% for current grater than 5 mA cm-2, and because of that, in the real system working area of the PANI electrode was five times greater than Zn electrode. For such system, good voltage characteristics during working 20 cycles were obtained. The open circuit voltage of 1.4 V was stable during 10 days. It was observed that the self discharge of the system was about 1.5% per day, which is in accordance to the self discharge of systems with PANI electrode

The use of anodic linear sweep voltammetery analysis (ALSV) for characterization the copper anodes used for sulphur acidic waste solution treatment

This paper addresses on investigation the possibility of electrolytic treatment the sulphur acidic waste solution, obtained in the conventional electrolytic copper refining process. The copper anodes with non-standard nickel, lead, tin and antimony content were specially prepared for the refining process. Nickel content of all anodes was approximately 7.5 mass %, and the content of lead, tin and antimony was varied. Results, obtained using the standard electrochemical techniques, have indicated that the anodes could be used under the same conditions as well as in the conventional copper refining process

Analyzing the corrosion characteristics of anodes used for the sulphur acidic waste water treatment

This paper addresses on investigation the possibility of electrolytic treatment the sulphur acidic waste solution, obtained in the conventional electrolytic copper refining process. The copper anodes with non-standard nickel, lead, tin and antimony content were specially prepared for the refining process. Nickel content of all anodes was approximately 7.5 mass %, and the content of lead, tin and antimony was varied. It was observed, that anodes with O2 content lower than 200 ppm, were not passivated. Results, obtained using the standard electrochemical techniques, have indicated that the anodes with non-standard chemical composition could be used under the same conditions as well as in the conventional copper refining process

Influence of chloride ion concentration on initial corrosion of AZ63 magnesium alloy

The initial corrosion behavior of AZ63 magnesium alloy was investigated in 1, 3, 5 and 7 wt.% NaCl solutions by means of corrosion potential, linear polarization, electrochemical impedance spectroscopy, and polarization measurements, during exposure in the corrosion media. Results show that the increase in chloride concentration provokes an increase in the corrosion rate. Based on the obtained kinetics parameters the mechanisms of anodic dissolution and hydrogen evolution reactions were discussed, and kinetic models were proposed. It is concluded that anodic dissolution proceeds under Temkin conditions and hydrogen evolution reaction depends on the surface coverage of Mg(OH)2 species

Electrochemical synthesis and characterization of poly(o-toluidine) as high energy storage material

Poly(o-toluidine) (POT) is electrochemically synthesized on graphite electrode at constant current density of 1.5 mA cm−2 from aqueous electrolyte of 1.0 mol dm−3 H2SO4 and 0.25 mol dm−3 o-toluidine. Electrochemical characterization of POT electrode is performed using cyclic voltammetry, Mot Schottky analysis and galvanostatic measurements at different currents. POT electrode exhibited high energy storage features, with specific energy up to 17.5 Wh kg−1 and specific power up to 3300 W kg−1. Cyclic stability exceeding 90% is obtained over 2000 charge/discharge cycles at 13.1 A g−1 indicating the perspective application of POT electrode as energy storage material.This is the peer-reviewed version of the following article: Gvozdenović, M., Jugović, B., Jokić, B., Džunuzović, E.,& Grgur, B.. (2019). Electrochemical synthesis and characterization of poly(o-toluidine) as high energy storage material. Electrochimica Acta, Pergamon-Elsevier Science Ltd, Oxford., 317, 746-752. [https://doi.org/10.1016/j.electacta.2019.06.046]Published version [http://technorep.tmf.bg.ac.rs/handle/123456789/4064

The influence of thin benzoate-doped polyaniline coatings on corrosion protection of mild steel in different environments

The corrosion process of mild steel in the presence of benzoate-doped polyaniline coatings exposed to different environments (3% NaCl, atmosphere, and the Sahara sand) has been investigated. This system was also tested for cathodic protection and it has proven more efficient comparing to mild steel alone. Possible mechanisms of the corrosion protection of mild steel in the presence of a polyaniline-based coating in different corrosion media were also proposed

Photo-assisted electrochemical oxidation of the urea onto TiO2-nanotubes modified by hematite

The electrochemical oxidation of the urea in near neutral pH is investigated on platinum electrode. It is shown that oxidation reaction is practically inhibited up to the potentials of similar to 0.9 V. The same reaction is investigated onto electrochemically obtained titanium dioxide nanotubes modified by hematite using facile, low-cost successive ion layer adsorption and reaction (SILAR) method. It is shown that such system possesses electrocatalytic activity at very low potentials, and activity can be further improved by the illumination of the electrode in the photo-assisted reaction. The possible application of the photoactive anode is considered in the application of urea based water electrolysis and urea based fuel cell

The influence of m-aminobenzoic acid on electrochemical synthesis and behavior of poly(aniline-co-(m-aminobenzoic acid)

Poly(aniline-co-(m-aminobenzoic acid)) was synthesized electrochemically at graphite electrode under galvanostatic conditions. Aqueous electrolyte for synthesis was consisted of HCl and different amount of aniline and m-aminobenzoic acid. The presence of the meta positioned carboxylic group in m-aminobenzoic acid influenced higher co-polymerization potential, different morphology and electrochemical behavior of copolymers compared to polyaniline. Electrochemical activity is achieved by proton exchange in neutral environment that can result in a faster charge/discharge process, which is in the case of PANI limited by slow anion exchange, making this material promising for consideration in super-capacitors and in biological system

Seawater zinc/polypyrrole-air cell possessing multifunctional charge-discharge characteristics

An environmentally friendly cell using polypyrrole-air regenerative cathode and zinc as anode is investigated in the 3% sodium chloride solution. The cell can operate in different charge and discharge mode. Polypyrrole can be reoxidized (doped) with chloride anions either by using dissolved oxygen or by an external power supply, e.g., small photovoltaic cell. In that way, after discharge, capacity retaining can be achieved by using seawater as the electrolyte. During low discharge rate, the delicate balance between solid state diffusion-controlled dedoping and chemical oxidation of polypyrrole produced by hydrogen peroxide is achieved, generating stable voltage plateau. The cell is proposed to operate as a power supply for different sensor devices in two modes. In the low discharge mode (10-20 mA g(-1)), it can be used for data acquisition, and at the fast discharge mode (up to 2 A g(-1)) for collecting data transmission