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Desulfovibrio bizertensis (D. bizertensis), an SRB isolated and cultured from the rust layer of the South China Sea, is widespread in the corrosive microbial communities on steel surface. Although the corrosion mechanism of SRB was widely studied, the mechanism of different metabolic stages inducing corrosion was still unclear. In this work, D. bizertensis was used to study the corrosion process of carbon steel Q235 at different metabolic stages by surface analysis and electrochemical methods. Combined with the metabolic process of SRB, corrosion pits of carbon steel could be influenced by two stages. In the first stage, the rapid growth of planktonic D. bizertensis cells in culture medium was accompanied by quick consumption of the electron donor (lactate) till complete consumption. D. bizertensis cells began to adhere to Q235 surface and promote anodic dissolution of iron. In the second stage, the growth of planktonic cells was suppressed, thus the colonized D. bizertensis cell in the pitting could obtain energy directly from Fe(0) through DET, which would further aggravate pitting corrosion and the maximum depth of the pits approached 15.7 µm. Sulfides produced by D. bizertensis metabolism would accumulate on steel coupon and form FeS coverage. Thus D. bizertensis could survive for a long time in this conductive FeS particles network. Electrochemical results showed the promotion effect of D. bizertensis on cathodic reaction, and the values of Rct in the SRB medium were much lower than that in the sterile medium.

Photocatalytic MoS2 with visible light response is considered as a promising bactericidal material owing to its non–toxicity and high antibacterial efficiency. However, photocatalysts always exist as powder, so it is difficult to settle photocatalysts on the metal surface, which limits their application in aqueous environments. To solve this problem, ultrasound and sodium dodecyl sulfate (SDS) were introduced into the co-deposition process of MoS2 and zinc matrix, so that novel MoS2–Zn coatings were obtained. In this process, ultrasound and SDS strongly promoted the dispersion and adsorption of MoS2 on the co-depositing surfaces. Then MoS2 were proved to be composited into the Zn matrix with effective structures, and the addition of SDS effectively increased the loading content of MoS2 in the MoS2–Zn coatings. Besides, the antibacterial performance of the MoS2–Zn coatings was evaluated with three typical fouling bacteria E.coli, S.aureus and B.wiedmannii. The MoS2–Zn coating showed high and broad–spectrum antibacterial properties with over 98 % inhibition rate against these three bacteria. Furthermore, it is proved that the MoS2–Zn coatings generated superoxide (·O2−) and hydroxyl radicals (·OH) under visible light, which played the dominant and subordinate roles in the antibacterial process, respectively. The MoS2–Zn coatings also showed high antibacterial stability after four “light–dark” cycles. According to the results of the attached bacteria, the MoS2–Zn coatings were considered to effectively repel the living pelagic bacteria instead of killing the attached ones, which was highly environmentally friendly. The obtained MoS2–Zn coatings were considered promising in biofilm inhibiting and marine antifouling fields.