Development of an environmentally friendly catalytic reaction system by controlling the pH inside hollow particles through electrode reactions

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05148
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 34030:Green sustainable chemistry and environmental chemistry-related
• Research Institution: Osaka University
• Principal Investigator: Harada Takashi 大阪大学, 大学院基礎工学研究科, 技術専門職員 (00379314)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 中空粒子 / 電極反応 / カプセル型構造体

Outline of Final Research Achievements

We immobilized capsule-type structures, which encapsulated titanium dioxide particles in hollow silica with different silica shell thicknesses, onto FTO electrodes and evaluated their photoelectrochemical properties. The findings revealed that the thicker the silica layer, the lesser the photocurrent detected under light irradiation. In the case of our capsule-type structure, it was estimated that with a silica shell thickness of approximately 40 nm, the photocurrent generated by titanium dioxide did not reach the electrode. Although we did not achieve application and verification for actual reaction systems using electrochemical reactions on the electrode, we confirmed that the conductivity can be controlled by the shell thickness of the non-conductive capsule structure.

Free Research Field

ナノ構造触媒

Academic Significance and Societal Importance of the Research Achievements

本研究では、非導電性の中空粒子に固体触媒を内包したカプセル型構造体を電極表面に配置し、電極上での電極反応により生じる電極近傍の局所的なpH勾配を利用して、中空粒子内部のpH制御を行い、中空内部を微小な反応場とする新たな反応系の構築を目指した。このような電極近傍のpH変化は、電極反応つまり外部につないだ電源によって簡単に細かな制御が可能となる。このような系が達成できれば、カプセル型構造体近傍でのみpHが変化するため、古典的な系の過剰量の酸・塩基による過反応を抑制でき、中和の必要も少なくなることから、現行の様々な有機合成プロセスへのインパクトは大きい。