TITLE:
Facile Synthesis of Ag/TiO2 by Photoreduction Method and Its Degradation Activity of Methylene Blue under UV and Visible Light Irradiation
AUTHORS:
Hwei-Cheng Tseng, Yu-Wen Chen
KEYWORDS:
Titanium Dioxide, Silver, Photocatalyst, Photoreduction, Photocatalytic Degradation of Methylene Blue
JOURNAL NAME:
Modern Research in Catalysis,
Vol.9 No.1,
December
17,
2019
ABSTRACT: A series of Ag/TiO2 with various Ag contents were prepared by
photoreduction method. Commercial TiO2 from Evonik-Degussa was used
as the catalyst. Ag was used as the cocatalyst. This facial synthesis method is
cheap and easy. TiO2 was suspended in water with various
concentrations of silver nitrate. The solution was illuminated by UV light for
36 h. Ag would deposit on the surface of TiO2. This method can
deposit all Ag cation in the starting material on TiO2 after 36 h
irradiation by UV light. X-ray diffraction, high resolution-TEM, and X-ray
photoelectron spectroscopy were used to characterize the surface, morphology
and chemical composition of the catalysts. Photocatalytic degradation of
methylene blue in water on these catalysts was carried out under UV and visible
light irradiation, respectively. The methylene blue concentration in water was
measured by a UV-vis spectrophotometer. The results showed that the bulk
structure of TiO2 did not change and some of Ag was incorporated
into the surface of TiO2 lattice. The change in the electronic state
of Ti on surface is attributed to the replacement of titanium atoms by silver
atoms on the TiO2 surface structure which induced visible light response
and enhanced the photocatalytic activity. 1 wt% Ag is the optimum loading to
have high activity.