The Cu-Sn-based catalysts are an effective and cheap alternative to precious metal-based catalysts for the photo-electrochemical reduction of CO2 to valuable products such as syngas and other chemicals. Cu oxides have been chosen for their behaviour and properties in CO2 reduction. Synthesis method for core-shell Cu2O-SnO2 was reported by Zhang et al. (2019) and it consists of Cu2O wet precipitation and then SnO2 impregnation. To obtain the Cu2O nanocubes are used: CuCl2, NaOH and C6H8O6 (L-Ascorbic Acid); after, for SnO2 impregnation, are employed SnCl4·5H2O and NaCl as reagents. To control the thickness of the SnO2 shell a Cu2O - SnCl4·5H2O molar ratio of five is set.