Electrochemical reduction of CO2 to carbon films on stainless steel around room temperature

Traditional electrodeposition of carbon films requires organic solvents or organic acids to serve as the carbon source. In this study, we demonstrated electrodeposition of carbon films from carbon dioxide (CO2) around room temperature. CO2 was dissolved in methanol with the help of elevated pressures, and tetrabutylammonium hexafluorophosphate was used as the conducting salt. Carbon films could be obtained at cell voltages above 3 V. The highest deposition rate of 979 nm h−1 was achieved. The effects of cell voltage and cell pressure on the film morphology, deposition rate and current efficiency were investigated. The mechanism of reduction of CO2 to carbon films was also proposed in this study. The electrodeposited carbon films exhibited good hydrophobicity. Keywords: Electrodeposition, CO2, Methanol, Carbon films, Hydrophobic