A high recombination rate and low charge collection are the main limiting factors of copper oxides (cupric and cuprous oxide) for the photocatalytic degradation of organic pollutants. In this paper, a high performance copper oxide photocatalyst was developed by integrating cupric oxide (CuO) and cuprous oxide (Cu₂O) thin films, which showed superior performance for the photocatalytic degradation of methylene blue (MB) compared to the control CuO and Cu₂O photocatalyst. Our results show that a heterojunction photocatalyst of CuO–Cu₂O thin films could significantly increase the charge collection, reduce the recombination rate, and improve the photocatalytic activity.