Enhanced activity of TiO2 by concentrating light for photoreduction of CO2 with H2O to CH4

Concentrating light technology is used to improve photoreduction of CO2 to CH4 reaction on semiconductor catalysts such as TiO2. The catalysts were prepared by anodization method and characterized by XRD, SEM, XPS and photoillumiation. The results showed that the CH4 yield rate could be raised from 0.70 μmol g−1 h−1 to 20.67 μmol g−1 h−1 under concentrating light, and it could be further increased to 28.49 μmol g−1 h−1 after pretreatment in the air. It is inferred that the concentrating light increases CO2 conversion not only by heightening light intensity, but also by improving the surface properties of the catalyst.