Development of a novel photocatalytic reaction system using photocatalytically accumulated electrons

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05666
• 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: Kyushu Institute of Technology
• Principal Investigator: Murakami Naoya 九州工業大学, 大学院生命体工学研究科, 教授 (10452822)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 光触媒 / トラップ電子 / 光音響

Outline of Final Research Achievements

In the present study, the energy level and the reactivity of accumulated electrons under a liquid-phase photocatalytic condition were studied by infrared photoacoustic spectroscopy. The results indicate that the reduction proceed by accumulated electrons at defective sites as well as conduction band electrons reexcited from trapped energy levels, and it strongly depends on kinds of the acceptor. Moreover, reduction of several acceptors (nitrobenzene, nitrate, carbon dioxide, proton) was performed by a time-separated redox reaction using photocatalytically accumulated electrons in a titanium(IV) oxide (TiO2) suspension. The time-separated redox reaction uses a two-step reaction under the control of photoexcitation and an electron acceptor: (1) accumulation of electrons in TiO2 powder under photoexcitation and (2) reduction of added acceptors by accumulated electrons in the dark.

Free Research Field

光触媒

Academic Significance and Societal Importance of the Research Achievements

本研究を遂行するために開発された分析系は，光触媒をはじめとする半導体材料の解析手法として有効であり，水分解による水素製造や二酸化炭素の資源化を可能にするようなエネルギー変換型の光触媒材料などの設計にも役立つと考えられる．また，本研究で構築した反応系は，これまで反応に寄与することはないと考えられていたトラップ電子を活用し，電子蓄積反応と電子放出反応の２段階の反応を行うことにより，酸化と還元の時間的な分離を行ったものである．これは，光触媒反応で問題となっている逆反応を根本的に解決する方法として有効であり，高選択的な光―物質返還へ応用できる可能性がある．