Application of He plasma irradiation to the preparation of a new photocatalyst

2014 Fiscal Year Final Research Report

• Project/Area Number: 24656489
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Catalyst/Resource chemical process
• Research Institution: Nagoya University
• Principal Investigator: YOSHIDA Tomoko 名古屋大学, エコトピア科学研究所, 准教授 (90283415)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 光触媒 / プラズマ照射

Outline of Final Research Achievements

The dendritic nanostructure was fabricated on a surface of tungsten plate by helium plasma irradiation. The nanostructure consisting of W metal was partially oxidized to form WO3 on exposure to air, and the resulting surface exhibited a broad photoabsorption in the range from 1 to 5 eV. We examined photoinduced reaction of methylene blue (MB) on the material. It was found that the partially and fully oxidized surface nanostructures were able to promote a decolorization of MB under photoirradiation even with the near-infrared light (<1.55 eV), whose energy is lower than the band gap of WO3. The reaction rate was varied with the fraction of W and WO3 on the surface layers, that is, the partially oxidized sample promoted the reaction at a higher rate than the fully oxidized one. It is also found that the reaction rate decreased with time, which would be caused by the products accumulation on the surface and the surface oxidation.

Free Research Field

触媒化学