On the synthesis and photochemical studies of nanostructured TiO_2 and TiO_2 admixed VO_2 photoelectrodes in regard to hydrogen production through photoelectrolysis

摘要

A new photoelectrode system TiO_2(ns)-VO_2 for photoassisted electrolysis of water is described. The nanostructured TiO_2 photoelectrode was prepared by the hydrolysis of titanium-tetrasiopropoxide followed by deposition of thin film by spin coating. To prepare the TiO_2(ns)-VO_2 photoelectrode, vanadium film was deposited on the TiO_2(ns) film and subsequently ocidized in O_2 ambient. The TiO_2(ns)-VO_2 photoelectrode exhibited enhanced photovoltage and photocurrent of 680 mV and 11.0 mA cm~(_2), respectively, whereas the TiO_2(ns) presented 540 mV and 3.2 mAcm~(-20, respectively. X-ray and S.E.M studies were carried out to monitor the surface and bulk characteristics of the TiO_2(ns)-VO_2 photoelectrode. The rate of hydrogen production under photoelectrolysis was found to be 6 i h~(-1)m~(-20 fro the TiO_2(ns) and ～ 13.01h~(-1)m~(-2) fro the TiO_2(ns)-VO_2 photoelectrode. The TiO_2(ns) photoelectrode shows the improvement in the PEC characteristics due to higher quantum yield resulting from the structured nature of the material. The PEC improvement in the TiO_2(ns)-VO_2 photoelectrode is due to the increase of range of absorption and the decrease of energy gap.