Semiconductor-septum photoelectrochemical solar cell for hydrogen production

In the present study, photo-electrochemical and hydrogen evolution characteristics of a new type of TiO2(ns) and TiO2(ns)-In2O3/Ti septum based semiconductor-septum photo-electrochemical (SC-SEP, PEG) solar cell has been studied. The SC-SEP cell in the configuration of SCE/1 M NaOH/TiO2(ns)/Ti/H2SO4+ K2SO4/Pt-CE Pt-WE showed the photo-voltage and photo-current of 0.72 V and 8.6 mA/cm(2), whereas the SC-SEP cell employing In2O3 admired TiO2(ns) photo-electrode and having the configuration: SCE/1 M NaOH/TiO2(ns)-In2O3/Ti/H2SO4 + K2SO4/Pt-CE? PtWE, showed the photo-voltage and photo-current of 0.92 V and 14.6 mA/cm(2), respectively. The hydrogen gas evolution for the SC-SEP cell based on TiO2(ns)/Ti photo-electrode was found to be 8.2 1/h m(2), on the other hand the In2O3 modified TiO2(ns) exhibited a higher hydrogen gas evolution rate of 11.8 1/h m(2). Evidence and arguments have been put forward to show that the presence of In2O3 over TiO2 makes the system posses the advantages of a colloidal photochemical system. The better performance of the new photo-electrode is thought to be due to improved spectral response and catalytic activity of In2O3 in regard to the hydrogen gas evolution kinetics. (C) 2000 international Association for Hydrogen Energy. Published by Elsevier Science Ltd. Ail rights reserved.