With the rising level of CO2 in the atmosphere, methods capable of converting CO2 into useful fuels are urgently needed. The electrochemical CO2 reduction has gained significant interest recently due to its ability to use renewable energies. However, the poor stability and selectivity of catalysts in electrochemical CO2 reduction limit its application in industry. Here a light-involving method has been developed to remove the surface carbonaceous species which are believed to poison the catalysts. A single atom catalyst based on Ni has also been investigated to have a high selectivity to CO in the electrochemical CO2 reduction.