Spectroelectrochemistry of highly doped nanostructured tin dioxide electrodes

A new, highly doped nanostructured SnO2:Sb electrode has been prepared. Thi s electrode possesses characteristics markedly different from undoped nanos tructured semiconductor electrodes. Cyclic voltammetry and spectroelectroch emical experiments reveal that the whole of the nanostructured SnO2:Sb elec trode is electronically addressed in a potential range extending from negat ive to significantly positive of the flatband potential. The flatband poten tial of nanostructured SnO2:Sb, obtained from the Mott-Schottky analysis, s hows Nernstian dependence on pH and is given by +0.10 - (0.06)(pH) (V vs Ag /AgCl). The extinction coefficient for conduction band electrons is determi ned to be 2400 M-1 cm(-1) at 700 nm. A theoretical model, based on; express ions derived for spherical semiconductor particles, fully accounts for the observed capacity-potential relation.