MoS<sub>2</sub>/Ag-TiO<sub>2</sub>/Polyurethane Nanocomposite as a Photocatalytic Coating for Antibiofouling Applications
Athira S. Vijayan, Abey Joseph, Baiju G. Nair, V. Sajith
Abstract
Marine biofouling continues to pose a major challenge for the maritime industries, affecting both vessels and stationary installations. Various types of antifouling coatings are being utilized on ship hulls and structures to inhibit the growth of fouling organisms. This study aims to explore the viability of employing MoS 2 /Ag-TiO 2 (MAT) incorporated polyurethane coatings on mild steel as an effective antifouling coating. MAT nanocomposites were synthesized using a liquid phase exfoliation process, and their structure and morphology were characterized using various spectroscopic and microscopic methods. The photocatalytic efficiency of the MAT nanocomposite was evaluated by measuring the degradation of crystal violet (CV) dye under sunlight, achieving an efficiency rate of 81%. Antibacterial tests on two microbial strains, Staphylococcus aureus ( SA ) and Pseudomonas aeruginosa ( PA ), revealed that the developed heterostructure had maximum photocatalytic killing activity for a concentration of 400 μg/mL for PA and 600 μg/mL for SA . Furthermore, the utilization of MAT coatings in marine structures was investigated using a marine water consortium to assess their effect on inhibiting biofilm formation. The findings demonstrated a significant reduction (∼95%) in bacterial adhesion compared to the uncoated surfaces, leading to a decrease in biofouling. Studies on microbial-induced corrosion demonstrate that MAT coatings display outstanding improvements in charge transfer resistance (4605 Ω) and coating resistance (7310 Ω) even after prolonged exposure to corrosive environments. The toxicity assessment conducted on the MAT nanocomposite toward L929 cell lines (mouse skin fibroblasts) and MG63 (human osteosarcoma) indicated an excellent biocompatibility with a cell survival rate of nearly 94% for a concentration of 400 μg/mL. This work demonstrates environment-friendly and cost-effective antibiofouling coatings employing the dual functionalities of photocatalysis and antibacterial properties of the MAT heterojunction.