Dual-function photoelectrode of TiO2 nanotube array/CdZnS/ZnS heterojunction for efficient photoelectrochemical cathodic protection and anti-biofouling

The low photoelectric conversion efficiency of photoelectrode is an important factor that limits the application in photoelectrochemical cathodic protection (PECCP) field for marine anti-corrosion of metallic structures. In this work, a photoelectrode of TiO2 /CdZnS/ZnS triple-phase heterojunction was fabricated by loading the narrow-band CdZnS associated with the broad-band ZnS via hydrothermal and continuous ion layer adsorption methods, respectively. The composite of CdZnS enhances the photoelectric conversion ability of TiO2 , while the ZnS composite can prevent the CdZnS from photo-corrosion and suppress the spillover of the photogenerated electrons. The three-phase heterostructure effectively improves the PECCP performance on 316 L stainless steel (SS) under simulated solar irradiation, especially in 3.5 wt% NaCl solution without the sacrificial agent. In addition, the prepared TiO2 /CdZnS/ZnS photoelectrode also performs anti-biofouling effect evidenced by the high removal efficiency of Pseudomonas aeruginosa ( P. aeruginosa ), which can be attributed to the oxidizability of photogenerated holes. The TiO2 /CdZnS/ZnS triple-phase heterojunction with desirable performance is a promising semiconductor material for the applications of PECCP and anti-biofouling. (c) 2024 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.