M(Cu, Ag, Pt)/TiO2覆膜光纖進行二氧化碳光催化還原

Abstract

In order to remedy the greenhouse gas CO2 and energy shortage, the photoreduction of CO2 is studied in a UV-illuminating steady-state gas photo-reactor with 216 optical fibers by a 100W high-pressure Hg lamp with wavelength 365nm at 348K. M(Cu, Ag, Pt)/TiO2 solutions were prepared by an improved thermal hydrolysis method. The optical fibers with the diameter of 0.1mm were coated by the dip-coating method. From the SEM micrographs, the catalyst layer had thickness about 30nm comprising fine spherical particles, which had diameter of 10-20nm and nano cavities between the crystallites. The XRD spectra showed all M(Cu, Ag, Pt)/TiO2 had anatase phase. From the UV-Vis spectra, the wavelength of absorption edge was near 350nm. The results of the XPS spectra revealed that Cu, Ag and Pt in the forms of Cu+, Ag0, Pt2+ or Pt4+ existed on TiO2 surface, respectively. The methanol yield increased with increasing UV irradiative intensity. The main product was methanol and other few products were formic acid and methyl formate. The loaded transition-metals (Cu, Ag, Pt) efficiently enhanced the methanol yield.