Fabrication of heterostructured β-Bi2O3-TiO2 nanotube array composite film for photoelectrochemical cathodic protection applications

Abstract An ordered TiO 2 nanotube array (NTA) film was first fabricated on a Ti substrate by anodization, β-Bi 2 O 3 nanoparticles were then electrodeposited on the film for obtaining a heterostructured β-Bi 2 O 3 -TiO 2 NTA composite film with enhanced photocathodic protection performances. Compared to the bare TiO 2 NTA film, the composite film showed a wider light absorption region and higher charge carrier separation efficiency. Under white light illumination, the composite film as a photoanode made the potential of 403 stainless steel in a 0.5 M NaCl solution decrease by 450 mV relative to its corrosion potential, showing an effective photoelectrochemical cathodic protection effect.