PHOTOELECTROLYSIS OF WATER AT BARE AND ELECTROCATALYST COVERED THIN-FILM IRON-OXIDE ELECTRODE

The photoelectrochemical effect on bare and electrocatalyst covered ir on oxide thin film electrodes for water splitting reaction has been st udied under both front and back illumination conditions. The semicondu cting iron oxide films of optimum thickness of similar to 33 nm, produ ced spray pyrolytically by 20 s spray time, gave the maximum photocurr ent density of 0.7 mA cm(-2). The band gap of the optimum thick film w as found to be 2.3 eV. Importantly, the photocurrent density under bac k illumination was found comparable to that under front illumination. The electrocatalyst ruthenium oxide reduced the onset potential of the iron oxide film by 120 mV but did not increase. the limiting photocur rent density. Lead oxide, manganese oxide and cobalt oxide deposited o n the iron oxide thin film did not show any electrocatalytic effect bu t rather reduced the photocurrent density compared to the bare iron ox ide film.