Highly Efficient CuInSe2 Sensitized TiO2 Nanotube Films for Photocathodic Protection of 316 Stainless Steel

Abstract

CuInSe2 nanoparticles were successfully deposited on the surface of TiO2 nanotube arrays (NTAs) by a solvothermal method for the photocathodic protection (PCP) of metals. Compared with TiO2 NTAs, the CuInSe2/TiO2 composites exhibited stronger visible light absorption and higher photoelectric conversion efficiency. After 316 Stainless Steel (SS) was coupled with CuInSe2/TiO2, the potential of 316 SS could drop to −0.90 V. The photocurrent density of CuInSe2/TiO2 connected to 316 SS reached 140 μA cm−2, which was four times that of TiO2 NTAs. The composites exhibited a protective effect in the dark state for more than 8 h after 4 h of visible light illumination. The above could be attributed to increased visible light absorption, the extended lifetime of photogenerated electrons, and generation of oxygen vacancies.