Electrochemical Properties of Nanoporous Carbon Electrodes

Abstract

Electrical double layer and electrochemical characteristics at the nanoporous carbon | (C 2 H 5 ) 4 NBF 4 + acetonitrile interface have been studied by the cyclic voltammetry and impedance spectroscopy methods. The value of zero charge potential (0.23 V vs. SCE in H 2 O), the region of ideal polarizability and other characteristics have been established. Analysis of complex plane plots shows that the nanoporous carbon | x M (C 2 H 5 ) 4 NBF 4 + acetonitrile interface can be simulated by the equivalent circuit, in which the two parallel conduction parts in the solid and liquid phases are interconnected by the double layer capacitance in parallel with the complex admittance of hindered reaction of the charge transfer process. The values of the characteristic frequency depend on the electrolyte concentration and on the electrode potential, i.e. on the nature of ions adsorbed at the surface of nanoporous carbon electrode.

The Electrochemical Behavior of 1-Ethyl-3-Methyl Imidazolium Tetracyanoborate Visualized by In Situ X-ray Photoelectron Spectroscopy at the Negatively and Positively Polarized Micro-Mesoporous Carbon Electrode

“…This high frequency arc characterizes the diffusion resistance of the B(CN) 4 − anions in the C(Mo 2 C) electrode micropores. 13,[65][66][67] It is notable in Fig. S1c that the width of this arc (i.e.…”

Comparison of carbon aerogel and carbide-derived carbon as electrode materials for non-aqueous supercapacitors with high performance

“…Taking into consideration the very narrow micropores on the CAG electrode surface, (partial) solvation shell removal has to occur for the diffusion of electrolyte ions into these pores (TEMA + ions may be too large to diffuse in micropores even with partial solvation shell) [1,5,6,14,15]. Thus, the slightly smaller C g values obtained at lower ΔE applied (ΔE<2 V) are probably explainable by inefficient solvation shell removal due to weaker electrostatic attraction forces in this region and higher effective Debye length values at lower electrode potentials [5,14,22].…”

“…The plots obtained for C(Mo 2 C)-based test cells were slightly more vertical (more pronounced ideal capacitive behaviour) at low frequencies, and there is a well-defined 'porous electrode section' in the middle-frequency region with a −45°slope (Fig. 3b, inset), where diffusion-like mass transfer process is the rate-limiting step [5,6,14,22]. For CAG-based system, the slope in middle-frequency region is less than −45° (Fig.…”

Adsorption kinetics of tetrabutylammonium cations on Bi() plane

“…In the region of maximal adsorption, C s decreases with increasing c cat . In the region of adsorption-desorption (E peak ), C s rises with the increase of concentration of the adsorbate in the solution and there is a nearly linear dependence of C s on ω 1/2 in the region of moderate frequencies, characteristic of the mainly diffusion-limited process [1][2][3][4][5][6][7][8][11][12][13][14][15][16]. At E > E σ=0 , adsorption of the I -ions takes place at Bi( 1 01 ) like Hg, Au and polycrystalline Bi [30][31][32], but these data can not be used for the quantitative analysis, because the surface oxidation of the Bi( 1 01 ) plane is possible at E > -0.5 V (Ag|AgCl).…”

“…charging and discharging times) of the edl capacitors. The impedance studies of the nanoporous carbon | non-aqueous tetrabutylammonium salt systems show very complicated kinetic behaviour [6,7] and, for that reason, the results for nearly ideally flat electrode are inevitable for the better understanding of the mechanism of processes, occurring at the surface of the nanoporous carbon electrode.…”