Mm. Khader et al., EFFECT OF PARTIAL REDUCTION ON ELECTRICAL AND PHOTOELECTROCHEMICAL PROPERTIES OF FERRIC-OXIDE, Journal of the Indian Chemical Society, 69(10), 1992, pp. 656-659
Reduction of ferric oxide in a mixture of H-2-H2O vapour, increases th
e conductivity due to doping by Fe(II). Re-oxidation of the reduced Fe
2O3 leads to gradual decrease of conductivity, upto a level much highe
r than that of the original material. The presence of Fe(II) introduce
s a donor level near to the conduction band of iron oxide resulting in
a decrease in the activation energy of conduction from 1.08 eV for st
oichiometric ferric oxide to 0.48 eV for the re-oxidised sample. While
the re-oxidised material exhibited anodic photoconductivity towards o
xygen evolution, neither the original Fe2O3 nor the reduced samples ar
e photoactive. The latter supports appreciable anodic and cathodic cur
rents in the dark.