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

The photoelectrochemical effect on bare and electrocatalyst covered iron oxide thin film electrodes for water splitting reaction has been studied under both front and back illumination conditions. The semiconducting iron oxide films of optimum thickness of similar to 33 nm, produced spray pyrolytically by 20 s spray time, gave the maximum photocurrent density of 0.7 mA cm(-2). The band gap of the optimum thick film was found to be 2.3 eV. Importantly, the photocurrent density under back 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 photocurrent density. Lead oxide, manganese oxide and cobalt oxide deposited on the iron oxide thin film did not show any electrocatalytic effect but rather reduced the photocurrent density compared to the bare iron oxide film.