A simple and efficient surface treatment method toward practical applications to enhance photo response of TiO₂ nanotube arrays (NTs) photoelectrode was reported. TiO₂ NTs were prepared by two-step electrochemical anodization methods, following by surface ultra violet light (UV) illumination treatment, which can produce amounts of hydroxyl groups on the surface of TiO₂ NTs photoelectrode. The photoelectrochemical measurements demonstrate that the photocurrent density of the UV treated TiO₂ NTs photoelectrode enhances by 50% than that of the pristine TiO₂ NTs photoelectrode. More interestingly, the decayed photocurrent density of TiO₂ NTs can recover the high value by illumination treatment again after using/storing for several days. Additionally, open circuit potential, tafel curves and electrochemical impedance spectroscopy measurements exhibit that the UV illumination treatment for TiO₂ NTs photoelectrode is an easy and effective strategy to protect 304 stainless steel from corrosion by photogenerated cathode protection.