  Silver-iron carbon nitride has been obtained by pyrolysis (under inert
atmosphere) of silver hexacyanoferrate(II), precipitated on graphene
nanoplatelets, and examined as electrocatalyst for oxygen reduction reaction in
alkaline media in comparison to silver nanoparticles and iron carbon nitride
(prepared separately in a similar manner on graphene nanoplatelets). The
catalytic materials have been studied in 0.1 M potassium hydroxide electrolyte
using such electrochemical diagnostic techniques as cyclic voltammetry and
rotating ring-disk electrode voltammetry. Upon application of graphene
nanoplateletssupported mixed silver-iron carbon nitride catalyst, the reduction
of oxygen proceeds at more positive potentials and the amounts of hydrogen
peroxide (generated during reduction of oxygen at potentials more positive than
0.3 V) are lower relative to silver nanoparticles and iron carbon nitride
(supported on graphene nanoplatelets) examined separately. Promoting effect is
ascribed to high activity of silver toward the reduction/decomposition of H2O2
in basic medium. Additionally, it has been observed that the systems based on
carbon nitrides show considerable stability due to strong fixation of metal
complexes to CN shells.
