A simple in situ method was developed to synthesize polypyrrole （PPy）/TiO2 nanocomposites hav- ing high photocatalytic activity under simulated solar light. The structure and morphology of the PPy/TiO2 nanocomposite...A simple in situ method was developed to synthesize polypyrrole （PPy）/TiO2 nanocomposites hav- ing high photocatalytic activity under simulated solar light. The structure and morphology of the PPy/TiO2 nanocomposites were characterized by X-ray powder diffraction （XRD）, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. The visible light photocatalytic properties of the nanocomposites were demonstrated by Rhodamine B degra- dation and by the production of methanol from CO2. The XRD analysis showed that the coating of PPy did not change the crystallinity of the TiO2. The UV-vis diffuse reflectance spectra indicated that the light adsorption range of the TiO2 was enlarged after modification. Energy-dispersive X-ray spectroscopy anal- ysis confirmed the presence of PPy and TiO2 in the nanocomposite catalyst. The RhB degradation using the nanocomposites was increased by 41% and the methanol yield was enhanced by 34 wt% in comparison with those obtained with pure TiO2. The improvements were considered to originate from the increased separation efficiency of hole-electron pairs from TiO2 and the enhancement of the light adsorption range by the introduced PPy.展开更多
文摘A simple in situ method was developed to synthesize polypyrrole （PPy）/TiO2 nanocomposites hav- ing high photocatalytic activity under simulated solar light. The structure and morphology of the PPy/TiO2 nanocomposites were characterized by X-ray powder diffraction （XRD）, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. The visible light photocatalytic properties of the nanocomposites were demonstrated by Rhodamine B degra- dation and by the production of methanol from CO2. The XRD analysis showed that the coating of PPy did not change the crystallinity of the TiO2. The UV-vis diffuse reflectance spectra indicated that the light adsorption range of the TiO2 was enlarged after modification. Energy-dispersive X-ray spectroscopy anal- ysis confirmed the presence of PPy and TiO2 in the nanocomposite catalyst. The RhB degradation using the nanocomposites was increased by 41% and the methanol yield was enhanced by 34 wt% in comparison with those obtained with pure TiO2. The improvements were considered to originate from the increased separation efficiency of hole-electron pairs from TiO2 and the enhancement of the light adsorption range by the introduced PPy.
