Fabrication of Ag–TiO2 nanocomposite employing dielectric barrier discharge plasma for photodegradation of methylene blue

Abstract

Ag nanoparticles have been incorporated in TiO2 to form Ag–TiO2 nanocomposite. The purpose was to enhance the photocatalytic activity of TiO2 in visible region. Ag–TiO2 nanocomposites were prepared using Dielectric Barrier Discharge Plasma operated at 14, 16 and 20 kV. XRD depicts the formation of cubic Ag with tetragonal geometry of TiO2. FTIR confirms the presence of Ag–O, Ti–O and Ag–O–Ti vibrations. UV-VIS shows that the TiO2 and pristine AgTiO2 do not have any absorption peaks in visible region. However, for 16 and 20 kV plasma treated samples, an absorption peak in visible region (580–720 nm) is observed. Evolution of this peak is because of the bandgap tuning from 3.15 to 2.31 eV. Ag–TiO2 based Photodegradation of methylene blue under UV, Plasma, and sunlight reveals that 16 kV Plasma treated Ag–TiO2 is the best under sunlight (93%). It is concluded that plasma treatment has activated Ag–TiO2 for photo degradation in the visible region.