Highly Efficient Photocathodic Protection Performance of 2D/2D ZIS@CNNs Composites under Visible Light

Abstract

Low separation efficiency of photogenerated carriers and inefficient utilization of visible light limit the application of g-C3N4 nanosheets (CNNs) in the field of photocathodic protection (PCP). Therefore, this work considered indium zinc sulfide (ZnIn2S4, ZIS) as a visible photosensitizer and an electronic donor to promote its PCP performance. ZIS nanolayers with nano-leaf structures were fabricated on CNNs by a simple hydrothermal method. The synthesized 30% ZIS@CNNs composites significantly enhanced the PCP performance for 316 stainless steel (SS) compared with pure CNNs. Under visible light illumination, the 30% ZIS@CNNs photoelectrode exhibited the largest photoinduced current density of 17.30 μA cm−2 and a photoinduced potential drop of 0.37 V, which was approximately 4 and 7.5 times higher than that of pure CNNs, respectively. The improved protection performance may be attributed to the significant increase in visible light absorption and the great enhancement in the separation efficiency of