Preparation of ZnWO4/TiO2 composite film and its photocathodic protection for 304 stainless steel under visible light.

ZnWO4/TiO2 composite films were fabricated on TiO2 substrate by hydrothermal method. The ZnWO4 nanorods-sensitized TiO2 coupled with 304 stainless steel was served as photoelectrode to study its anticorrosion effect for metal. Under visible light, the photocathodic protection ability of TiO2 and ZnWO4/TiO2 composite film was measured by photoelectrochemical program on potentiostat. Open circuit potential variation result showed that sanmartinite ZnWO4 nanorods could enhance the photoelectrochemical activity of TiO2, and the ZnWO4/TiO2 composite films could absorb energy and store electrons to play a role in corrosion protection for metal.