A novel g-C3N4/In2O3/BiVO4 heterojunction photoanode for improved the photoelectrochemical cathodic protection of 304 SS stainless steel under solar light

Recently, photocathodic protection has been regarded as one of the environment-friendly techniques for metal's anti-corrosion. In this technique, n-type semiconductor photoanode produces photogenerated electrons to reparation the lost electrons from metals. Therefore, significant efforts have been made to develop materials with facile methods for improving metals photocathodic protection. Herein, g-C3N4/In2O3/BiVO4 trinary system composite was synthesized through a novel approach. The XRD, UV, and PL techniques were used to confirm the enhancement in photogenerated electrons. Furthermore, the photoelectrochemical results showed that the prepared samples increased the negativity of the 304 SS stainless steel under open circuit potential (OCP) conditions. Additionally, the potential of the 304 SS polarization showed a negative shift from − 505 to − 625 mV and − 635 mV after joined to In2O3/BiVO4 and C3N4/In2O3/BiVO4, respectively. Moreover, the presence of g-C3N4 was provided extra cathodic protection, providing polarization potential more negative during light off. That expects the insertion of this material into the offshore facilities coating to increase its lifetime and decrease corroded metals' discharge into the water bodies.