Cu₂O–Cu was successfully electrodeposited onto a carbon paper substrate through a potentiostatic procedure with a three-electrode configuration. The results demonstrate that the Cu₂O–Cu, electrodeposited at a potential of −0.4 V, evenly and uniformly grows on the carbon paper and displays octahedron shaped nanoparticles with an average edge length of 100 nm. Moreover, the photocurrent density of Cu₂O–Cu electrodeposited at a potential of −0.4 V can reach up to 1.2 mA cm⁻². In this Cu₂O–Cu, the interface between the Cu₂O and Cu is suggested as the location of photoinduced electron–hole pair separation, and thus it hinders the rapid surface and bulk recombination of the photoinduced electron–hole pairs. Consequently, the photogenerated electrons can be easily transferred through the Cu metal .