A review of the development of photoelectrochemical cathodic protection from the perspective of hole scavengers and interface synergy

Metal corrosion is a long-term challenge faced by mankind, and the complex marine environment (high temperature, high humidity, and high salt) makes the protection of marine equipment particularly complex. Photoelectrochemical (PEC) cathodic protection technology has become a research hotspot in the field of marine metal protection due to its environmentally friendly and sustainable characteristics. Semiconductors are the core of controlling anti-corrosion performance, but their photoelectric conversion efficiency is limited by the efficiency of capturing photogenerated holes. In the actual marine environment, there are no efficient hole scavengers, so it is necessary to promote the advancement of this technology through in-depth research into the hole capture mechanism. This article systematically summarizes the PEC cathodic protection system without the addition of hole scavengers, takes hole capture as the entry point, and systematically discusses the factors affecting the photoelectric conversion efficiency from multiple interface perspectives (coating interface, heterojunction interface, hole capture interface), providing a new perspective for the subsequent development of PEC cathodic protection.