TY - JOUR
T1 - Unexpected redox rectification by an electrochemically prepared iridium oxide electrode/aqueous acid interface
AU - Johnson, Christopher S.
AU - Hupp, Joseph T.
PY - 1993/2/15
Y1 - 1993/2/15
N2 - In highly acidic aqueous solutions, electrochemically prepared iridium oxide films behave as steady-state insulators and transient rectifiers towards the Ru(NH3)63+/2+ redox couple. In less acidic solutions the films show only partial transient rectification or else fully reversible transient behavior, together with Koutecky-Levich-type steady-state behavior. Experimental studies, as a function of Ru(NH3)63+ concentration, solution pH, film thickness, voltammetric sweep rate and electrode rotation rate, show that these unusual phenomena are related to: (1) transient uptake of Ru(NH3)63+, apparently in place of H+, during film-based Ir(IV/III) cycling; (2) Donnan exclusion of Ru(NH3)63+ from the reduced film under steady-state conditions; and/or (3) film-based diffusional inhibition of Ru(NH3)63+ reduction.
AB - In highly acidic aqueous solutions, electrochemically prepared iridium oxide films behave as steady-state insulators and transient rectifiers towards the Ru(NH3)63+/2+ redox couple. In less acidic solutions the films show only partial transient rectification or else fully reversible transient behavior, together with Koutecky-Levich-type steady-state behavior. Experimental studies, as a function of Ru(NH3)63+ concentration, solution pH, film thickness, voltammetric sweep rate and electrode rotation rate, show that these unusual phenomena are related to: (1) transient uptake of Ru(NH3)63+, apparently in place of H+, during film-based Ir(IV/III) cycling; (2) Donnan exclusion of Ru(NH3)63+ from the reduced film under steady-state conditions; and/or (3) film-based diffusional inhibition of Ru(NH3)63+ reduction.
UR - http://www.scopus.com/inward/record.url?scp=4043082041&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4043082041&partnerID=8YFLogxK
U2 - 10.1016/0022-0728(93)80489-5
DO - 10.1016/0022-0728(93)80489-5
M3 - Article
AN - SCOPUS:4043082041
SN - 0022-0728
VL - 345
SP - 351
EP - 362
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
IS - 1-2
ER -