Effective Solar Light Photocatalysis by Graphene Sheets (GSs) Addition on the Composite TiO<sub>2</sub>/SiO<sub>2</sub>
Keywords:Photocatalyst, Graphene sheet, TiO2/SiO2, sol-gel method
This study investigated the synthesis of TiO2/SiO2 by using a sol-gel method with the addition of difference of the mass ratio of Titanium (Ti):Graphene Sheets (GSs) (1:0; 1:0.04; 1:0.07; 1:0.14) and the variation of calcination temperature (Tcal) (400 ℃; 450 ℃; 500 ℃). The synthesized composites were analyzed by X-ray powder diffraction (XRD) and Scanning electron microscope and energy dispersive X-ray spectrometer (SEM-EDS). The TiO2/SiO2/GSs XRD pattern shows anatase and rutile phases as well as graphite at the near point of 2θ (26°-27°). The tendency of anatase phase according to GSs ratio and Tcal variables is decreasing with an increase in the GSs ratio and Tcal. The crystal size was in the range of 24 – 41 nm. The decolorization of methylene blue was done under four conditions: dark, UV lamp, LED, and solar light. The photocatalytic activity result under solar light is comparable with UV light. The photocatalyst with a ratio at 0.07 and Tcal at 450 ℃ gave the maximum efficiency of MB decolorization under solar light with 97.83 % within 3 hours. The reusable TiO2/SiO2/GSs show a slight fall in efficiency after four cycle times.
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