EFFECT OF PARTIAL REDUCTION ON ELECTRICAL AND PHOTOELECTROCHEMICAL PROPERTIES OF FERRIC-OXIDE

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.