A review on recent progress in the development of photoelectrodes for photocathodic protection: Design, properties, and prospects

Metal corrosion is a long-term challenge facing mankind. Thanks to its green, environmentally friendly, sustainable properties, photocathodic protection (PCP) technology have become hot research for metal anti-corrosion in the past decade. In this technology, an n-type semiconductor as an electron donor (photoanode) to provide continuously injected photoelectrons to the metal substrate (cathode), causing negative shift self-corrosion potential to achieve anti-corrosion. Therefore, the design and preparation of highly efficient photoelectrode materials is currently an urgent research topic. Herein, we reviewed the most common strategy used in the preparation and modification of highly efficient photoelectrodes, discussed how to design highly efficient and functional photoelectrodes in detail, and highlighted some examples of photoelectrodes with unique and impressive properties. Then, some potential novel functional materials, energy storage mechanism and in-situ protection technology were reviewed to equip the readers with the latest research trends. Finally, we discuss the outlook and remaining challenges practical in the field of PCP industrial-scale application. • Some commonly strategies for design efficient photoelectrode are elaborated. • Highlight some TiO 2 -based photoelectrodes with unique and impressive properties. • Energy storage photoelectrodes and in-situ protection technology are summarized. • Current challenges and perspectives for future research are discussed.