Yoshinari Konishi

Utilization of Titanate Nanotubes as an Electrode Material in Dye-Sensitized Solar Cells

In this study, titanate H 2 Ti 3 O 7 nanotubes with a multiwall structure, synthesized by a hydrothermal process, were successfully used as an electrode material for dye-sensitized solar cells. The best efficiency, 7.5%, was achieved for an opened cell under illumination of simulated AM 1.5 solar light (100 mW cm -2 ). The relationship between the photovoltaic performance and physicochemical properties of titanate nanotube was also investigated.

High‐Throughput Screening of Iron‐Based Oxide Photoelectrodes for Solar Hydrogen Generation

Iron oxide (Fe2O3) is a visible‐light‐responsive n‐type semiconductor, and its photoactivity for photo‐electrochemical water decomposition has often been investigated. In this study, we aimed to determine an optimum composition for a photoelectrode based on an n‐type iron‐based oxide semiconductor made from binary or ternary metal oxides using a high‐throughput screening system for visible‐light‐responsive semiconductors. We examined the photocurrent properties of various combinations of iron and metals with various composition ratios and observed higher photocurrents than those observed for pure iron oxide in some combinations, for example, in Fe–Ti, Fe–Zr, Fe–V, and Fe–Ti–Zr systems. In the Fe–Ti–Zr system, we observed the highest photocurrent at Fe/Ti/Zr = 60:10:30, which is also higher than the photocurrent observed for TiO2 under both ultraviolet and visible‐light irradiation. These iron‐based oxide photoelectrodes could replace Fe2O3 electrodes as top electrodes in a tandem cell used to split water ...