Influence of operational parameters on the photocatalytic activity of powdered TiO₂ for the reduction of CO₂

In this report, the results from a study on the influence of operational parameters on TiO₂ photocatalytic activity for CO₂ reduction under an ultraviolet-visible (UV-vis) illumination are presented. The results indicated that the TiO₂ was found to be active for CO₂ reduction with CH₃OH as the major products, while other minor products (CO, CH₄, and C₂H₄) were also detected. In addition, the formation of such reduction products was obviously influenced by the operational parameters. Under this study, the optimum operational parameters for CO₂ reduction at 298 °K were determined to be: NaOH concentration 0.2 M, TiO₂ dosage 2 g/L, volume of the reaction media 75 mL, the pressure of system 800 kPa. It was also found that the increase in UV-vis illumination time have increased the yield of product formation. A possible reaction pathway for the formation of the reduction products is also discussed.