Boosted photoelectric cathodic protection exerted by 3D TiO2/AgInS2/In2S3 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 AgInS2/In2S3 co-modified TiO2 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 AgInS2/In2S3, the quasi-Fermi level of the photogenerated electrons of TiO2 NB/AgInS2/In2S3 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 AgInS2 together with the assistant layer In2S3 dramatically enhances the PECP performance of TiO2 NB/AgInS2/In2S3. The tri-dimensional ultrafine branch-like architecture of TiO2 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. The tri-dimensional AgInS2/In2S3 co-modified TiO2 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. [ABSTRACT FROM AUTHOR]