Impact of molar ratio of NH3 and H2O on CO2 reduction performance over Cu/TiO2 photocatalyst

Abstract

Cu-doped TiO2 (Cu/TiO2) film photocatalyst was prepared by sol-gel dip-coating, and pulse arc plasma process. The netlike glass fiber was used as a base material for the photocatalyst since it had a porous structure. The CO2 reduction performance with NH3 and H2O into CO and CH4 over the Cu/TiO2 photocatalyst was investigated experimentally under the illumination condition with UV as well as without UV. In addition, the characterization of prepared Cu/TiO2 film coated on netlike glass fiber was analyzed by SEM and EPMA. As a result, the CO2 reduction performance peaks under the condition of CO2/NH3/H2O=1:1:1 in both cases with UV light and without UV light illumination. The highest molar quantity of CO and CH4 per weight of photocatalyst in the reactor is 10.2 μmol/g and 1.76 μmol/g, respectively. Comparing the CO2 reduction characteristics for CO2/NH3/H2O with that for CO2/H2O, it is concluded that the proper combination of NH3 and H2O would be effective for promoting the CO2 reduction performance over Cu/TiO2, for the improving of the reduction performance of Cu/TiO2 being necessary to promote the conversion from NH3 into H2.