Electroanalysis using modified hierarchical nanoporous carbon materials

RUSBEL CONEO RODRIGUEZ; A. BAENA MONCADA; DIEGO F. ACEVEDO; GABRIEL A. PLANES; MARIA C. MIRAS; CESAR A BARBERO

FARADAY DISCUSSIONS

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2013 vol. 164 p. 147 - 173

1364-5498

The role of the electrode nanoporosity in electroanalytical processes is discussedand specific phenomena (slow double layer charging, local pH effects) which canbe present in porous electrode are described. Hierarchical porous carbon (HPC)materials are synthesized using a hard template method. The three dimensionalcarbon porosity is examined using scanning electron microscopy on flat surfacescut using a focused ion beam (FIB-SEM). The electrochemical properties of theHPC are measured using cyclic voltammetry, AC impedance,chronoamperometry and Probe Beam Deflection (PBD) techniques.Chronoamperometry measurements of HPC seems to fit a transmission linemodel. PBD data show evidence of local pH changes inside the pores, duringdouble layer charging. The HPC are modified by in situ (chemical orelectrochemical) formation of metal (Pt/Ru) or metal oxide (CoOx, Fe3O4)nanoparticles. Additionally, HPC loaded with Pt decorated magnetite (Fe3O4)nanoparticles is produced by galvanic displacement. The modified HPC materialsare used for the electroanalysis of different substances (CO, O2, AsO3
3). The role of the nanoporous carbon substrate in the electroanalytical data is evaluated.