SEMICONDUCTIVE PROPERTIES AND PHOTOELECTROCHEMISTRY OF IRON-OXIDE ELECTRODES .8. PHOTORESPONSES OF SINTERED ZN-DOPED IRON-OXIDE ELECTRODE

The photoelectrochemical behaviour and semiconductive properties of Zn-doped sintered polycrystalline iron oxide were investigated in boric acid/borax buffer solution (pH = 8.4). Strange characteristic photoresponses of n-type semiconductive electrodes at a more positive potential, p-type semiconductive electrodes at a more negative potential and both n-type and p-type semiconductive electrodes at an intermediate potential have been measured. Through a series of experiments, a possible explanation of this phenomenon has been proposed, ie the existence of heterogeneity both on the surface and in the bulk of the electrode leads to different behaviour of the electrode at different external potentials.