Ultrasound assisted electrodeposition of photocatalytic antibacterial MoS-Zn coatings controlled by sodium dodecyl sulfate.

Photocatalytic MoS 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 MoS and zinc matrix, so that novel MoS-Zn coatings were obtained. In this process, ultrasound and SDS strongly promoted the dispersion and adsorption of MoS on the co-depositing surfaces. Then MoS were proved to be composited into the Zn matrix with effective structures, and the addition of SDS effectively increased the loading content of MoS in the MoS-Zn coatings. Besides, the antibacterial performance of the MoS-Zn coatings was evaluated with three typical fouling bacteria E.coli, S.aureus and B.wiedmannii. The MoS-Zn coating showed high and broad-spectrum antibacterial properties with over 98 % inhibition rate against these three bacteria. Furthermore, it is proved that the MoS-Zn coatings generated superoxide (·O) and hydroxyl radicals (·OH) under visible light, which played the dominant and subordinate roles in the antibacterial process, respectively. The MoS-Zn coatings also showed high antibacterial stability after four "light-dark" cycles. According to the results of the attached bacteria, the MoS-Zn coatings were considered to effectively repel the living pelagic bacteria instead of killing the attached ones, which was highly environmentally friendly. The obtained MoS-Zn coatings were considered promising in biofilm inhibiting and marine antifouling fields.