Enhanced photocathodic protection performance of TiO2/SnO2/CdIn2S4 composites for 304 stainless steel in marine environments

In humid and saline environments, metal corrosion leads to significant economic losses, necessitating enhanced anti-corrosion methods. This study aims to enhance the photocathodic protection (PCP) performance of TiO2 nanotubes (NTs) by incorporating SnO2 quantum dots (QDs) and CdIn2S4 nanoflowers (NFs). TiO2 NTs were fabricated on titanium substrates via anodization, followed by successive deposition of SnO2 QDs and CdIn2S4 NFs using immersion and hydrothermal methods. The composite materials were characterized using SEM, TEM, XRD, and XPS. The PCP performance was evaluated through electrochemical tests on 304 stainless steel (304ss). The TiO2/SnO2/CdIn2S4 (T/S/C) composite exhibited a photocurrent density seven times that of pure TiO2 NTs, indicating significantly enhanced separation ability. The composite also demonstrated a notable open-circuit potential (OCP) of -1045 mV vs. SCE. Furthermore, T/S/C could provide delayed protection for up to 10 h in the dark, indicating its electron storage capability. The T/S/C composite material enhances the corrosion resistance of 304ss, offering a promising approach for practical anti-corrosion applications.