Photocatalytic Activity of Vis-Responsive Ag-Nanoparticles/TiO2 Composite Thin Films Fabricated by Molecular Precursor Method (MPM)

Catalysts

Likius S. Daniel¹  Hiroki Nagai²  Naoya Yoshida² 

[1] Department of Applied Chemistry and Chemical Engineering, Graduate School, Kogakuin University, 2665-1 Nakano, Hachioji City, Tokyo 192-0015, Japan; E-Mail:;Research Institute of Science and Technology, Kogakuin University, 2665-1 Nakano, Hachioji City, Tokyo 192-0015, Japan; E-Mails:

关键词: photocatalyst;    Ag NP;    molecular precursor method;    methylene blue;    surface plasmon;   

DOI  :  10.3390/catal3030625

来源: mdpi

【 摘 要 】

The Ag-nanoparticles (Ag-NP)/TiO₂ composite thin films with various amounts of Ag (10 mol% ≤ n ≤ 80 mol%) were examined as a potential photocatalyst by decoloration reaction of methylene blue (MB) in an aqueous solution. These composite thin films of ca. 100 nm thickness were fabricated by the MPM at 600 °C in air. The decoloration rates monitored by the absorption intensity of the MB solution indicated that the composite thin films of Ag with an amount less than 40 mol% are not effective under vis-irradiation, though they can work as a photocatalyst under UV-irradiation. Further, the UV-sensitivity of the composite thin films gradually decreased to almost half the level of that of the TiO₂ thin film fabricated under the identical conditions when the Ag amount increased from 10 to 40 mol%. Contrarily, the composite thin films of Ag content larger than 50 mol% showed the vis-responsive activity, whose level was slightly lower than the decreased UV-sensitivity. Diffuse reflectance spectra suggested that the vis-responsive activity of the composite thin films is due to the conductivity, localized surface plasmon resonance and surface plasmon resonance of Ag-NP. It was also elucidated that the vis-responsive level of the composite thin films corresponds to their electrical conductivity that depends on the Ag content.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.