Highly enhanced photoelectrochemical cathodic protection performance of the preparation of magnesium oxides modified TiO2 nanotube arrays

Abstract

The magnesium oxide modified TiO2 nanotube arrays (TiO2 NTs) was prepared to investigate the photoelectrochemical (PEC) cathodic protection performance to 304 stainless steel (SS 304). With the annealing treatment at different temperature, the surface of the modified materials changed remarkably. The film-like Mg(OH)2 obtained at 400°C transformed to MgO particles after treatment at 500°C and 600°C. Further thermal processing at 700°C enables MgTixOy@TiO2 shell-core structure. Using photoelectrochemical approaches to study the series samples, the cathodic protection performance of the modified TiO2 NTs has significantly improved. The magnesium oxides modified TiO2 NTs treated at 600°C (Ti-Mg-O 600) shows the best PEC cathodic protection to the underneath steel. Further investigation shows that the highly enhanced PEC cathodic protection performance of Ti-Mg-O 600 was attributed to the effective separation of photogenerated carriers, the increase of carrier concentration and the negative shift of the conduction band potential.