Development of high-efficiency photoelectrode for solar water splitting utilizing ferroelectric polarization

2018 Fiscal Year Final Research Report

• Project/Area Number: 17H06608
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Energy-related chemistry
• Research Institution: The University of Tokyo
• Principal Investigator: Matsuo Hiroki 東京大学, 大学院新領域創成科学研究科, 特任助教 (10792517)
• Project Period (FY): 2017-08-25 – 2019-03-31
• Keywords: 光電極 / 水分解 / スズ酸化物 / 強誘電体 / 水素製造 / パルスレーザー堆積法 / 格子欠陥 / 薄膜

Outline of Final Research Achievements

Development of hydrogen production technologies utilizing renewable energies has been demanded to realize CO2-free hydrogen society. In this research, thin-film water splitting photoelectrodes which can decompose water to hydrogen and oxygen under irradiation of sunlight was developed. Thin-film photoelectrodes with visible-light-active semiconducting oxides of Sn2TiO4 and SnNb2O6 containing Sn2+ ion were prepared by a pulsed-laser deposition method. Relation between water splitting activity of the photoelectrodes and lattice defects in the semiconducting oxides were clarified. In addition, an influence of introducing a ferroelectric thin layer in the photoelectrodes on the water splitting performance was investigated.

Free Research Field

酸化物薄膜合成および電気化学

Academic Significance and Societal Importance of the Research Achievements

太陽光エネルギーを利用した水素製造方法の一つとして，可視光を吸収する半導体光電極による水分解が挙げられる．可視光領域に吸収を持つSn2TiO4およびSnNb2O6は粉末での光電極への研究がなされてきたが，高特性化が期待できる薄膜型光電極の研究は，その薄膜合成の難しさからこれまでに報告されていない．本研究ではこれらの材料の薄膜光電極の開発に成功し，水分解活性が発現することを示した．格子欠陥と性能との関連や強誘電体層の導入効果を検証し，今後の性能向上に向けた指針を示した．