Porous coated electrode

Figure 3.69 Cyclic voltammograms (v = 20 mV s-1) ofthin porous coating electrodes containing 4.4% w/w H2TMPP XC-72 (A), 4.7% w/w CoTMPP XC-72 (B) and 4.8% w/w (FeTMPP)20 XC-72 (C) in 0.05 M H2S04. The upper and lower curves in each ofthe panels were...

Surfaces roughened by very fine shot blasting or by application of porous coatings (electrode-posited porous metals, ceramics, anodizing, or phosphatizing) can better retain lubricants and thus help to prevent corrosion. 

Fig. 1 shows the cyclic voltammetry of an FePc/XC-72 dispersion, heated at 280°C in an inert atmosphere, in the form a thin porous Teflon bonded coating electrode in a 1 M NaOH solution. A description of the methodology involved in the preparation of this type of electrode may be found in Ref. 3. As can be clearly seen, the voltammetry of this specimen exhibits two sharply defined peaks separated by about 330 mV. The potentials associated with these features are essentially identical to those found by other workers for the reduction and oxidation of films of iron oxy-hydroxide formed on a number of host surfaces, including iron and carbon.(5)... 

Nanocarbons can also be deposited onto surfaces via electrochemistry, such as electrophoretic deposition described earlier. A method for one-step electrochemical layer-by-layer deposition of GO and PANI has been reported by Chen et al. [199]. A solution of GO and aniline was prepared and deposited onto a working electrode via cyclic voltammetry. GO was reduced on the surface when a potential of approx. -1 V (vs. SCE) was applied compared to the polymerization of aniline which occurred at approx. 0.7 V (vs. SCE). Repeated continuous scans between -1.4 to 9 V (vs. SCE) resulted in layer by layer deposition [199]. A slightly modified method has been reported by Li et al. who demonstrated a general method for electrochemical RGO hybridization by first reducing GO onto glassy carbon, copper, Ni foam, or graphene paper to form a porous RGO coating [223]. The porous RGO coated electrode could then be transferred to another electrolyte solution for electrochemical deposition, PANI hybridization was shown as an example [223]. 

Wang, R., Okajima, T., Kitamura, R, and Ohsaka, T., A novel amperometric O2 gas sensor based on supported room-temperature ionic liquid porous polyethylene membrane-coated electrodes, Electroanalysis, 16, 66-72, 2004. 

The definition of the electrochemical Thiele modulus [Eq. (9b)J characterizing the degree of electrocatalyst utilization is a prerequisite for properly tailoring the micromorphology of porous electrocatalytic electrode coatings and fuel cell electrodes, as it allows matching of the coating or catalyst particle dimension to the catalytic activity of the material ... 

In the thermal-electrolytic-type AgCl electrode, silver is formed by heating a paste of silver oxide coated on a spiral of platinum wire. Part of the spongy silver mass in converted to AgCl by the electrolysis process described above. Because the silver is porous, the electrodes tend to be rather sluggish, but they can be prepared with very small bias potentials ( 20 jtV). 

Perez J, Gonzalez ER, Ticianelli EA (1998) Impedance studies of the oxygen reduction on thin porous coating rotating platinum electrodes. J Electrochem Soc 145 2307-13... 

Preliminary conductivity measurements indicate that the polymers based on the anionic system are ionically conductive, whereas the nonionic based polymers are non-conductive. AC impedance tests were done on a thick film ( limn thick) using sodium sulfate as the electrolyte in a specially designed closed cell. The resistivity of polystyrene obtained from middle phase microemulsions was found to be in the rjange of lOMO ohm-cm, compared to lO o -10 2 ohm-cm for bulk polystyrene. A thin film of the polymer was also obtained on graphite electrodes by UV irradiation. Electrochemicd measurements using such polymer coated electrodes also suggest that the film is conductive. SEM micrographs before and after the electrochemical measurements indicate that the polymeric film is stable and porous. 

It consisted of a solid electrolyte disk (thickness 2 mm) made of yttria (8.5 wt. %) stabilized zirconia, which was coated with the same active component (cf. 2.3.) used in the reactor on the measuring side, and with a porous platinum electrode on the reference side. The measuring... 

Electrochemical studies of the electrocatalysts were carried out using the thin porous coating technique [12,13]. An amormt of 20 mg of the eletrocatalyst was added to a solution of 50 mL of water containing 3 drops of a 6% polytetrafluoroethylene (PTFE) suspension. The resulting mixture was treated in an ultrasound bath for 10 min, filtered and transferred to the cavity (0.30 mm deep and 0.36 cm area) of the working electrode. The quantity of electrocatalyst in the working electrode was determined with a precision of... 

Perez, J, E.R, Gonzalez, and E.A. Ticianelli, Oxygen electrocatalysis on thin porous coating rotating platinum electrodes. Electrochimica Acta, 1998, 44 pp. 1329-1339 Song, H,-K, H,-Y, Hwang, K.-H. Lee, and L.H, Dao, The effect of pore size distribution on the frequency dispersion of porous electrodes. Electrochimica Acta, 2000. 45 pp. 2241-2257 Srikumar, A, T.G. Stanford, and J.W, Weidner, Linear sweep voltammetry in flooded porous electrodes at low sweep rates. Journal of Electroanalytical Chemistry, 1998. 458 pp. 161-173... 

Jung, Y.S., Cavanagh, A.S., Gedvilas, L., Widjonarko, N.E., Scott, I.D., Lee, S.H., Kim, G.H., George, S.M., Dillon, A.C., 2012. Improved functionality of lithium-ion batteries enabled by atomic layer deposition on the porous microstructure of polymer separators and coating electrodes. Adv. Energy Mater. 2, 1022-1027. 

Lima FHB, Ticianelli EA (2004) Oxygen electrocatalysis on ultra-thin porous coating rotating ring/disk platinum and platinum-cobalt electrodes in alkaline media. Electrochim Acta 49 4091-4099... 

In this way, a stimulation electrode is formed where a porous coating of an insulating parylene film is partially deposited. The porosity of the film is continuously decreasing with the film thickness. This issue allows precisely defined windows in the parylene film and high reproducibility in the production of the stimulation electrodes. 

Porous carbon electrodes coated with catalysts Aluminium-vanadium mixed oxides H2SO4 Oxidation Wiesener (1973)... 

The successful use of ruthenium-coated porous Ti electrodes coupled with the benefits of adopting back-flow configuration [43] is strongly suggestive that there are combinations of physical architecture, flow configurations and electrode functionalization with good operational capability stiU awaiting discovery. 

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