p-CuO films and photoelectrochemical corrosion

•CuO films were analyzed photoelectrochemically with various reducible species.•Cathodic photocurrents rapidly decayed due to the conduction band electron reduction of CuO to Cu2O.•Annealing in air resulted in the reconstruction of the CuO layer and full photocurrent recovery.•The presence of an electron scavenger results in only minor long-term stabilization.•High concentrations of electron scavengers could not be used due to the high cathodic dark currents.