Dramatic CO2 photoreduction with H2O vapors for CH4 production using the TiO2 (bottom)/Fe-TiO2 (top) double-layered films

This paper reports the production of a catalyst for the efficient photoreduction of CO2 to CH4. TiO2 and x mol.% Fe-doped TiO2 (Fe-TiO2, x = 0.5, 1.0, 5.0, 10.0 mol.%) were prepared using a conventional solvothermal method. The prepared powders were fabricated as TiO2 (bottom)/Fe-TiO2 (top) double-layered films for applications to the photoreduction. of CO2. The amount of CH4 generated from the photoreduction of CO2 with H2O increased remarkably over the TiO2/Fe-TiO2 double-layered photocatalytic films compared to the TiO2 (bottom)/TiO2 (top) double layered film. In particular, the amount of CH4 gas evolved over the TiO2/1.0 mol.% Fe-TiO2 doubled layered film was 7 times higher than that produced over the TiO2 (bottom)/TiO2 (top) double layered film. A proposed model suggested that the photoactivity over the TiO2/Fe-TiO2 double layered films can be enhanced by the effective charge separation and inhibited recombination of photogenerated electron-hole (e-/h+) pairs on interfacial transfer between TiO2 and Fe-TiO2. (C) 2015 Elsevier B.V. All rights reserved.