The Impact of Amount of Cu on CO₂ Reduction Performance of Cu/TiO₂ with NH₃ and H₂O

Abstract

This study has investigated the impact of molar ratio of CO2 to reductants NH3 and H2O as well as that of Cu loading on CO2 reduction characteristics over Cu/TiO2. No study to optimize the reductants’ combination and Cu loading weight in order to enhance CO2 reduction performance of TiO2 has been investigated yet. This study prepared Cu/TiO2 film by loading Cu particles during the pulse arc plasma gun process after coating TiO2 film by the sol-gel and dip-coating process. As to loading weight of Cu, it was regulated by change in the pulse number. This study characterized the prepared Cu/TiO2 film by SEM and EPMA. Additionally, the performance of CO2 reduction has been investigated under the illumination condition of Xe lamp with or without ultraviolet (UV) light. It is revealed that the molar ratio of CO2/NH3/H2O is optimized according to the pulse number. Since the amount of H+ which is the same as that of electron is needed to produce CO decided following the theoretical CO2 reduction reacting with H2O or NH3, larger H+ is needed with the increase in the pulse number. It is revealed that Cu of 4.57 wt% for the pulse number of 200 is the optimum condition, whereas the molar quantity of CO per unit weight of Cu/TiO2 with and without UV light illumination is 34.1 mol/g and 12.0 mol/g, respectively.

Keywords

• Cu/TiO₂ film photocatalyst
• CO₂ reduction characteristics with NH₃ and H₂O
• Cu loading weight
• optimum combination of reductants
• visible light response