A p-type cuprous oxide (Cu₂O) photocathode covered with a thin layer of cupric oxide (CuO) was prepared by fast annealing of a copper foil via H₂–O₂ flame. The as-prepared composite photocathode is characteristic of a junction structure formed between the (110) plane of Cu₂O and the (111) plane of CuO. The Cu₂O/CuO composite photocathode showed improved stability for photoelectrochemical (PEC) water reduction by increasing the coverage of CuO on Cu₂O.