The interaction of electropolymerized Co(III)TAPP (polyCoTAPP) films with adsorbed resorcinol on glassy carbon (GC) and with surface quinone functionalities on aerogel carbon (AEC) were studied using reflection UV-visible spectroscopy and X-ray photoelectron spectroscopy. A red shift of the Soret band and the appearance of new Q bands appearing after adsorption of resorcinol on a GC/polyCoTAPP film was interpreted as being due to change of the metalloporphyrin electronic structure. The photoelectron depth profiles for an AEC/polyCoTAPP film showed that the cobalt ion is mostly in the Co(III) state at the outer layers of the film, while the amount of cobalt ion in the formal +2 state gradually increases in the inner film layers. This seems to indicate the formation of charge-transfer complexes between the metalloporphyrin and reduced quinone functionalities on the AEC surface. Understanding the nature of metalloporphyrin/porous carbon structures is an important step toward the design of reliable and low-cost non-noble-metal oxygen reduction catalytic electrodes and their application in fuel cells and batteries.
|Number of pages||4|
|Journal||Journal of Physical Chemistry Letters|
|State||Published - Jan 2010|