NiCo-layered double hydroxide modified TiO2 nanotube arrays and its application in photoelectrochemical cathodic protection of 304 stainless steel

NiCo-layered double hydroxide (NiCo-LDH) modified TiO2 (NiCo/TiO2) were prepared by a simple electrochemical deposition method. The morphology, chemical composition, light adsorption and photoelectrochemical (PEC) properties of these composites were fully characterized. The performance of NiCo/TiO2 in PEC cathodic protection of 304 stainless steel (304 SS) was investigated in NaCl solution. The results showed that NiCo(-0.8)/ TiO2 had the best PEC cathodic protection performance, as indicated by the largest photo-induced potential drop (-440 mV) of 304 SS. It was proposed that a type II heterojunction was built between NiCo-LDH and TiO2, leading to a more efficient separation of photo-generated charge carriers.