Manganese indium sulfide/indium oxide with S-scheme heterojunction for enhanced dual performance of metal in marine environment

‘Chinese peony’-structured MnIn₂S₄/In₂O₃ nanocomposites with S-scheme heterojunction were prepared, and their dual performance of anticorrosion for steels and wastewater purification was explored. The mechanism for the enhanced photoelectrochemical cathodic protection (PECCP) is attributed to the introduction of S-scheme MnIn₂S₄/In₂O₃ heterojunction, which was systematically certificated through density functional theory (DFT) and experiments. Furthermore, MnIn₂S₄/In₂O₃ PECCP coating was synthesized to compensate for the insufficient dark protection capability of PECCP and defined through inductively coupled plasma (ICP). The protection efficiency of MnIn₂S₄/In₂O₃PECCP coating was 75.33% and 96.22% for 304 stainless steel (304SS) and hot-rolled ribbed bar 400 (HRB400) in 3.5 wt% NaCl for 54 days. In addition, the improved mechanism for anticorrosion of the PECCP coating was investigated by the wire beam electrode (WBE).