Investigation on the formation behavior of noble metal alloy nanoparticles during anodization and its control and applications

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01752
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26050:Material processing and microstructure control-related
• Research Institution: Osaka University
• Principal Investigator: Hiroaki Tsuchiya 大阪大学, 工学研究科, 准教授 (50432513)
• Co-Investigator(Kenkyū-buntansha): 藤本 愼司 大阪大学, 工学研究科, 教授 (70199371)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: アノード酸化 / チタニア / ナノチューブ / 貴金属 / ナノ粒子 / 自己組織化 / チタン合金

Outline of Final Research Achievements

Anodization, the electrochemical oxidation of metal by applying voltage in electrolyte, forms porous oxide layers under the optimized electrolyte and voltage. This work aims at revealing the optimized anodization which can simultaneously realize the porous TiO2 layer formation and the deposition of noble metal nanoparticles on the layer by anodizing Ti alloys containing noble metals as such structures are found to enhance the hydrogen evolution through the water splitting. When the amount of alloying elements is large, homogeneous porous layer was not grown. Although homogeneous porous layer was obtained when the amount is small, on the other hand, the deposition of nanoparticles was not confirmed at low applied voltage. However, the anodization of the Ti alloys at higher voltage led to the formation of homogeneous porous layer where nanoparticles were highly dispersed. These imply that the optimized amount of alloying element and anodization voltage are desired to achieve the process.

Free Research Field

材料電気化学

Academic Significance and Societal Importance of the Research Achievements

本研究は水の光分解による水素生成に用いる、貴金属ナノ粒子が担持した光触媒をチタン合金のアノード酸化によりナノ構造を有するTiO2担体の形成とナノ粒子担持を同時に実現するための条件を見出したことは学術的に意義があるといえる。また研究代表者らが行ってきた一連のチタン合金の成果と併せると、チタンのアノード酸化における合金元素の役割を系統的に理解することができ、この点も当該分野の深化に貢献できる。