In this paper, four composite coatings of nano-SnS/polyvinylbutyral (PVB), nano-MoS₂/PVB, nano-SnS-Zn/PVB, and nano-MoS₂-Zn/PVB were prepared, and their anti-corrosion mechanism was analyzed by experimental and theoretical calculations. The results of the electrochemical experiments show that the effect of nano-MoS₂ on the corrosion protection performance of PVB coating is better than that of nano-SnS in 3% NaCl solution, and that the addition of Zn further enhances this effect, which is consistent with the results of weight loss measurements. Furthermore, the observation of the corrosion matrix by the field emission scanning electron microscope (FESEM) further confirmed the above conclusion. At last, the molecular dynamics (MD) simulation were carried out to investigate the anti-corrosion mechanism of the nanofillers/PVB composites for the copper surface. The results show that both nano-SnS and nano-MoS₂ are adsorbed strongly on the copper surface, and the binding energy of nano-MoS₂ is larger than that of nano-SnS.

This paper presents the anti-corrosion application of polyvinylbutyral/tin sulfide (PVB/SnS) composites for the first time, where the liquid-phase exfoliated (LPE) SnS nanosheets are uniformly embedded in the PVB matrix. The measurement results of the potentiodynamic polarization, the electrochemical impedance spectroscopy (EIS) and the scanning electronic microscopy (SEM) show that PVB/SnS composite coatings show the excellent corrosion protection behavior for copper under 3.0% NaCl solution. Besides, we investigated the anti-corrosion performance with different contents of SnS nanosheets. The results show that embedding 0.1 wt% SnS nanosheets in the PVB matrix can greatly improve the anti-corrosion properties of the coating due to the enhanced "Labyrinth effect" of the coatings. In addition, the results of the molecular dynamic analysis further show the high interaction energy between PVB/SnS composites and copper, which is attributed to the high aspect-ratio of LPE-SnS nanosheets. Moreover, the scratch tests reveal that the PVB/SnS composite coatings exhibit weak corrosion-promotion activity, indicating a promising potential application in the corrosion protection of the metal surface for ocean engineering. The methods for enhancing the inhibited corrosion-promotion activity of the semiconductor material SnS-based composite coatings could be expanded to other n-type and p-type semiconductors.