Development of organic/inorganic hybrid catalyst based on a distorted porphyrin

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05254
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: University of Tsukuba
• Principal Investigator: Kotani Hiroaki 筑波大学, 数理物質系, 助教 (10610743)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 酸化チタン / ポルフィリン / 酸素 / 水 / 電子移動 / 光触媒

Outline of Final Research Achievements

We designed an organic-inorganic hybrid photocatalyst for production of hydrogen peroxide (H2O2) by using water as an electron source. The organic-inorganic hybrid photocatalyst was prepared by immobilizing diprotonated dodecaphenylporphyrin (H4DPP2+) derivatives having carboxyl groups as a linker to the surface of TiO2 for photocatalytic formation of H2O2 in pure water. The H4DPP2+-TiO2 hybrid photocatalyst was dispersed in pure water, then the resulting aqueous suspension was irradiated at 365 nm using an LED lamp under air. Formation of H2O2 was confirmed by iodometry of the supernatant and the amount of H2O2 was determined to be 0.3 mM for 1 min photoirradiation. Thus, it is proposed that the H4DPP2+-TiO2 hybrid photocatalyst performs water oxidation at the TiO2 surface and selective two-electron reduction of O2 at the H4DPP2+ moiety, respectively.

Free Research Field

光化学

Academic Significance and Societal Importance of the Research Achievements

本研究で開発した有機無機ハイブリッド触媒を用いることで、紫外線照射のみで水を電子源として酸素を選択的に還元することで光触媒的に過酸化水素を生成可能な光触媒系の構築に成功した。今回得られた成果では、酸化チタン表面上に有機触媒を担持することによって、固体触媒としての触媒耐久性だけでなく分子触媒としての反応選択性を併せ持つことが判明した。この有機無機ハイブリッド触媒によって、水を電子源とする新たな光触媒系への展開が可能となる。