Introduce of oxygen vacancies into the metal oxides and amount control of these by unique soft synthetic process

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05659
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
• Research Institution: Utsunomiya University
• Principal Investigator: Matsumoto Taki 宇都宮大学, 機器分析センター, 准教授 (00419417)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 酸化チタン / 酸化ジルコニウム / 酸素欠陥 / 光触媒

Outline of Final Research Achievements

Low-dimensional growth titanium and zirconium oxides were used as starting materials, and were mixed with hydroxylamine as a nitrogen source. When the sample was calcined under vacuum, a large amount of oxygen vacancies ware introduced. For the titanium oxide system, the content of oxygen vacancy can be controlled by the re-calcination temperature in oxygen-containing stream to partially oxidize the introduced oxygen vacancies, while can not for the zirconium oxide system. The control of the content of oxygen vacancies in the zirconium oxide system was achieved by controlling the degree of vacuum during calcination.
When the photocatalytic activity of the obtained samples was evaluated under visible light irradiation, a significant dependence of the photocatalytic activity on the amount of oxygen vacancies was observed in the titanium oxide system, while in the zirconium oxide system, no dependence was observed.

Free Research Field

無機合成化学

Academic Significance and Societal Importance of the Research Achievements

本研究では高温高圧を必要としないソフトなプロセスにより化学的に安定な4族、5族の金属酸化物中に「酸素欠陥」を導入する新たなプロセスを開発したことで、欠陥導入型金属酸化物材料の応用、適用領域が今後いっそう広がるものと考えられる。特に酸素欠陥量が精密に制御された欠陥導入型金属酸化物の合成が可能となったことから、これらに関して光触媒活性やORR活性を評価し酸素欠陥量の影響を明確化することで、特異な光電気化学特性の発現機構の解明および光触媒／電極触媒材料の高度化・高活性化につながるものと期待される。