Surface-plasmon-enhanced photocatalytic H2 generation and CO2 conversion over metal nanoparticles

Research Project

Project/Area Number	19K15311
Research Category	Grant-in-Aid for Early-Career Scientists
Allocation Type	Multi-year Fund
Review Section	Basic Section 26040:Structural materials and functional materials-related
Research Institution	Osaka University
Principal Investigator	Verma Priyanka 大阪大学, 工学研究科, 特任助教(常勤) (60837318)
Project Period (FY)	2019-04-01 – 2020-03-31
Project Status	Discontinued (Fiscal Year 2019)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2019: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Keywords	photocatalysis / plasmonic nanoparticles / mesoporous materials / microwave chemistry / CO2 utilization
Outline of Research at the Start	This proposal is aimed at creating a design platform for the fabrication of nanocatalysts for the photocatalytic hydrogen generation from ammonia borane, formic acid and conversion of carbon dioxide to renewable transport fuels such as methanol using plasmonic nanoparticles.
Outline of Annual Research Achievements	The main purpose of this research is to design and develop visible-light sensitive photocatalysts which can efficiently capture and utilize the available solar energy to chemical energy. To extend the research studies on plasmonic nanocatalysts, we synthesized Au nanoparticles (NPs) on different morphologies of TiO2 support material. Different morphologies of TiO2 (nanotube, nanorod and microporous) were prepared by the hydrothermal treatment of anatase TiO2 with different alkali hydroxides such as NaOH, KOH and LiOH at 400 K for 30 h. These TiO2 nanotube/nanorod/microporous particles were then used to accommodate Au NPs for carrying out the photocatalytic reaction because of its high surface area and large pore volume. It was observed from the reaction results that the aerobic oxidation of benzyl alcohol was significantly enhanced by the plasmonic excitation of Au NPs under visible light irradiation, especially in the case of TiO2 nanotube and nanorod as the support material. Based on spectroscopic analyses, it was concluded that the charge separation effect arising from the localized surface plasmon resonance of Au NPs caused a simultaneous oxidation and reduction of substrate (electron donor) and O2 (electron acceptor) at different sites. Although extended studies utilizing this Au/TiO2 plasmonic catalyst to H2 production and CO2 reduction have not been done yet, we predict that such progress in the design of new catalysts by utilizing solar energy will definitely foster the development of clean photocatalytic system.