Impedance of porous gold electrodes in the presence of electroactive species

Impedance of Porous Electrodes

“…For long pores and at very negative potentials the ratio of the low and high frequency limits of the faradaic impedance equals two and the complex plane plot of the total impedance displays two identical semicircles. Formation of two semicircles for a simple red-ox couple was observed experimentally (22). C , the current might be expressed in terms of the overpotential: O / R m C C .…”

Novel dynamic effects in electrocatalysis of methanol oxidation on supported nanoporous TiO2 bimetallic nanocatalysts

“…The open, tunable in size, nanochannel structure offers new advantages for studying catalyst-support interactions. The impedance analysis of such a nanochannel catalytic material has recently been performed by Lasia and co-workers [152]. In the present work, the film formation was investigated using voltammetry, EQCN technique, pulse potentiostatic methods and AFM imaging.…”

Gold-coated magnetic nanoparticles as “dispersible electrodes” – Understanding their electrochemical performance

“…This conclusion is supported by EIS of a solution of potassium ferricyanide or of a redox couple with much slower electron transfer kinetics, cobalt phenanthroline in a 1 M solution of H 2 SO 4 (Fig. SI5), which show no evidence of the double semi-circle Nyquist plot characteristic of a porous electrode [27]. Fig.…”

“…Two types of redox probes were used: (1) 1 mM ferricyanide in PBS solution for measuring the resistance of the Au@MNPs film. (2) 0.1 M cobalt(II) 1,10-phenanthroline for the determination of any possible porous structures [27] was prepared by mixing stoichiometric amounts of cobalt(II) sulphate and 1,10-phenantholine in a solution of 1 M sulphuric acid. A Nyquist plot (Z 0 vs -Z 00 ) was displayed in zView and the internal resistance modeled by the program.…”