CO₂ reforming characteristics under visible light response of Cr- or Ag-doped TiO₂ prepared by sol-gel and dip-coating process

Abstract

<jats:p>A Cr- or Ag-doped TiO<jats:sub>2</jats:sub>film was prepared by sol-gel and dip-coating process and used as the photocatalyst for CO<jats:sub>2</jats:sub>reforming under the visible light. The ratio of amount of Cr or Ag added to amount of Ti in TiO<jats:sub>2</jats:sub>sol solution (<jats:italic>R</jats:italic>) varied from 0 to 100 wt% or 0 to 50 wt%, respectively. The total layer number of Cr- or Ag-doped TiO<jats:sub>2</jats:sub>film (<jats:italic>N</jats:italic>) coated was changed. The CO<jats:sub>2</jats:sub>reforming performance with the Cr- or Ag-doped TiO<jats:sub>2</jats:sub>film was tested under a Xe lamp with or without ultraviolet (UV) light. As a result, when<jats:italic>N</jats:italic>equals to 1, the concentration of CO which was a product from CO<jats:sub>2</jats:sub>reforming was maximized in Cr doping case for<jats:italic>R</jats:italic>= 70 wt% and in Ag doping case for<jats:italic>R</jats:italic>= 1 wt%, respectively. The best result of concentration of CO = 8306 ppmV, concentration of CH<jats:sub>4</jats:sub>= 1367 ppmV, concentration of C<jats:sub>2</jats:sub>H<jats:sub>6</jats:sub>= 1712 ppmV is obtained when with Cr doping in this study.</jats:p>