Development of efficient metal oxynitride photoelectrodes for water splitting under visible light irradiation by controlling carrier density

2014 Fiscal Year Final Research Report

• Project/Area Number: 25888013
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Energy-related chemistry
• Research Institution: Kyoto University
• Principal Investigator: HIGASHI Masanobu 京都大学, 工学(系)研究科(研究院), 助教 (10711799)
• Project Period (FY): 2013-08-30 – 2015-03-31
• Keywords: 光電極 / 水分解 / 酸窒化物 / ドーピング / キャリア密度 / 可視光

Outline of Final Research Achievements

A tantalum oxynitride BaTaO2N possesses appropriate band levels for water splitting as well as absorption edge up to 660 nm. We have recently reported that pre-treatment of BaTaO2N particles with a H2 stream at high temperature significantly increased photocurrent due to increased donor density, however, the precise control was difficult via this method. Thus, we attempted to dope various metals into BaTaO2N to control donor density in the present study, and found that doping of Ni2+ or Mo6+ resulted in a significant improvement of photocurrent. Furthermore, loading of CoOx as a cocatalyst for O2 evolution resulted in a significant improvement of photocurrent and stability, and enabled us to split water into H2 and O2 at stoichiometric ratio under visible light irradiation.

Free Research Field

光電気化学