Photoelectrochemical Reduction of CO2 in Methanol with TiO2 Photoanode and Metal Cathode

This work focuses on the photoelectrochemical CO2 reduction at TiO2 photoanode and metal cathode in methanol-based electrolyte. The TiO2 nanotube photoanodes were obtained by anodization of Ti plate (30 x 20 mm) and calcination. The emphasis is placed on evaluating and comparing the current density and Faradaic efficiencies at different calcination temperatures, calcination times and cathodes (Pb and Ag). A result for calcination condition suggested that the optimum program of TiO2 photoelectrode was the calcination at 700 degrees C during 2 hours. The formation of carbon monoxide and methyl formate was monitored during UV radiation (365 nm) at an applied potential of 2.0 V vs. Ag QRE. The main product by photoelectrochemical reduction of CO2 with Pb cathode was methyl formate whereas it with Ag cathode was carbon monoxide.