Improved photocathodic protection performance of C-vacancy g-C3N4/GO/WO3 for 304 stainless steel

In this work, C-vacancy g-C3N4/GO/WO3 composite was prepared by calcination method, and its composition, morphological characteristics and electrochemical properties were systematically analyzed. Compared with C-vacancy g-C3N4 and WO3, the photocathode protection effect of C-vacancy g-C3N4/GO/WO3 for 304 stainless steel was improved. The AC impedance results showed that, compared with C-vacancy g-C3N4, the Rct value of C-vacancy g-C3N4/GO/WO3 coupled with 304 stainless steel decreased from 1841 Ω cm2 to 21.31 Ω cm2. A heterostructure of WO3 and C-vacancy g-C3N4, obviously improved the catalytic effect of composite materials, and GO reduced the Fermi level of the system. The possible mechanism of photogenerated cathodic protection was analyzed in detail.