Performance enhancement of a-Fe2O3@Bi2S3 heterojunction for photocathodic protection of 304SS

Hematite (alpha-Fe2O3) is one of the most promising candidates as a photoanode for photocathodic protection (PCP) of 304SS. However, serious charge recombination has hindered the application. In this work, we verified the feasibility of constructing heterojunction for enhancing the PCP performance. alpha-Fe2O3@Bi2S3 can not only broaden the solar light absorption region but also provide a built-in electric field to improve charge separation and close junctions for charge transport. When alpha-Fe2O3@Bi2S3 was coupled with 304SS, the OCP under illumination negatively shifted to -0.788 V-Ag/AgCl, which was ca. 600 mV negative than the corrosion potential of 304SS. The photoinduced current density reached 32 mu A cm(-2), outperforming the bare Bi2S3 and alpha-Fe2O3. The formation of a type II heterojunction between Bi2S3 and alpha-Fe2O3 was proposed and verified by the electrochemical impedance measurements.& nbsp;