Construction of new catalyst preparation method using solution plasma and rational design of artificial photosynthetic catalyst

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18856
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 27:Chemical engineering and related fields
• Research Institution: Osaka Metropolitan University (2022); Osaka City University (2021)
• Principal Investigator: Yoshida Tomoko 大阪公立大学, 人工光合成研究センター, 教授 (90283415)
• Co-Investigator(Kenkyū-buntansha): 山本 宗昭 大阪公立大学, 人工光合成研究センター, 特任助教 (50823712)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: 液中プラズマ法 / 二酸化炭素還元 / 光触媒

Outline of Final Research Achievements

Silver nanoparticles (Ag NPs) were synthesized by a solution plasma method in an aqueous solution. Optical emission spectra of the plasma revealed that Ag NPs are fabricated with the sputtering of Ag rods as electrode. In-situ optical absorption measurements of the solution during the discharge, which controlled the size of Ag NPs. The synthesized Ag NPs were loaded on gallium oxide, and the sample was used for photocatalytic CO2 reduction with water
Although the photocatalytic reaction proceeded over the sample to produce CO, the CO production rates decreased with the reaction time. Measurements of DR UV-vis spectra and TEM images revealed that a part of the Ag NPs aggregated to become larger particles during the photocatalytic reaction, which would be related to the decrease of the photocatalytic activity.

Free Research Field

触媒化学

Academic Significance and Societal Importance of the Research Achievements

液中で生成するプラズマの特性を活かした独創的且つ新しい触媒調製法を構築し，助触媒の高度設計手法へと，世界に先駆けて展開を図るというチャレンジを行っている．
（意義１）金属ナノ粒子合成法としての挑戦・特色は，ナノ粒子の凝集抑制のために従来使用された分散剤や配位子を利用しないことであり，触媒反応に適した清浄表面を持つナノ粒子助触媒を合成する点にある．（意義２）XAFS, FT-IR, 光吸収測定などの複合分析によって，助触媒の原子構造や化学・電子状態を評価することにより，「光触媒活性・反応メカニズムに及ぼす金属ナノ粒子担持効果」について単純明快な議論を展開する．