Innovative and efficient materials conversion by bio-inorganic photocatalyst

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K18213
• Research Category: Grant-in-Aid for Challenging Research (Pioneering)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 36:Inorganic materials chemistry, energy-related chemistry, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Ishihara Tatsumi 九州大学, 工学研究院, 教授 (80184555)
• Co-Investigator(Kenkyū-buntansha): Song Juntae 九州大学, 工学研究院, 助教 (10865348)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 光触媒 / バイオ触媒 / 物質変換

Outline of Final Research Achievements

This research was mainly studied on 1) increasing the efficiency of inorganic photocatalysts, 2) developing new biophotocatalytic reactions, and 3) developing photoelectrochemical cells. As for subject 1), Eosin Y showed a good sensitizing effect, and the AQY for visible light at 520 nm was as high as 1.5%. In combination with hydrogenase, STH for hydrogen formation in the presence of a sacrificial agent was as high as 2.5%. As for subject 2), ammonia synthesis using nitrogenase was studied as a new reaction, and it was possible to synthesize large quantities of nitrogenase by modifying the culture medium, and formation of NH3 and H2 was successfully demonstrated. As for subject 3), electrochemical cell using TiO2 as the positive electrode was studied, and reduction of MV and oxygen formation were achieved by applying a voltage of about 0.1 V under light irradiation.

Free Research Field

触媒化学

Academic Significance and Societal Importance of the Research Achievements

現在、カーボンニュートラルエネルギー社会の達成が強く求められている。本研究では光エネルギーを直接、水素として固定するために、効率の高い光触媒として、バイオ触媒と無機触媒を組み合わせるというコンセプトで、通常は、平衡の制約がある反応で、平衡を超えて、大きな効率で水素やアンモニアを合成できることを示した。とくにアンモニアは現在、肥料として必要不可欠であり、エネルギー消費の大きいハーバーボッシュ法で作成されているが、今回、室温、常圧で、気相N2と水からNH3と水素が合成できる可能性を示すことができたので、今後は、さらに生成速度を向上することで、環境調和なアンモニア合成プロセスになる可能性がある。