Photocathodic protection properties of TiO2-V2O5 composite coatings

TiO2/vanadium pentoxide (V2O5) and TiO2–V2O5 coatings were prepared on type 304 stainless steel substrates via a sol–gel method, respectively. The TiO2/V2O5 coating is compared with the TiO2–V2O5 coating in terms of the photo‐electrochemical performance. The two coatings can be stored with photogenerated electrons under UV irradiation in 3 wt% aqueous NaCl. The self‐discharging time of the TiO2/V2O5 coating is slower than that of the TiO2–V2O5 coating. The slow discharging may be suitable for an anti‐corrosion application for stainless steel. In the case while the two coatings are electrochemically charged under UV irradiation for 1 h, the TiO2/V2O5 coating can maintain a good cathodic protection for type 304 stainless steel for 6 h in the dark, while the TiO2–V2O5 coating can only maintain a good cathode protection for 0.5 h in the dark.