Boosted photoelectric cathodic protection exerted by 3D TiO 2 /AgInS 2 /In 2 S 3 nanomultijunction for pure copper in NaCl solution

The global annual consumption of marine metal corrosion is a significant challenge to the service life of metals and the development of marine strategies. A tri-dimensional AgInS 2 /In 2 S 3 co-modified TiO 2 nanobush (NB) superstructure photoanode is constructed. It shows superior photoelectric cathodic protection (PECP) characteristic for pure copper whose self-corrosion potential is more negative in simulated natural marine environment without additional any hole scavengers under simulated solar light illumination. Origin from the more negative energy level potential of AgInS 2 /In 2 S 3 , the quasi-Fermi level of the photogenerated electrons of TiO 2 NB/AgInS 2 /In 2 S 3 was pull to a more negative position, reinforcing the transmission of photogenerated electrons to the pure copper whose self-corrosion potential is more negative. The sensitizer AgInS 2 together with the assistant layer In 2 S 3 dramatically enhances the PECP performance of TiO 2 NB/AgInS 2 /In 2 S 3 . The tri-dimensional ultrafine branch-like architecture of TiO 2 NB with the nanoparticles quickens the collection and transfer of photogenerated electrons to the metallic pure copper. This environmentally friendly 3D photoanode structure provides a good reference for the optimized construction of photoelectric materials for marine metal corrosion protection. Graphical abstract The tri-dimensional AgInS 2 /In 2 S 3 co-modified TiO 2 nanobush superstructure photoanode possesses superior photoelectric cathodic protection characteristic for pure cooper whose self-corrosion potential is more negative in simulated marine environment under simulated solar light illumination.