Development of Antibacterial V/TiO₂-Based Galvanic Coatings for Combating Biocorrosion

Abstract

Recently, TiO2 crystals have been modified by transition-metal dopants with different physicochemical structures to attain distinguished properties. Considering the similar ionic sizes of V4+ (0.058 nm) and Ti4+ (0.061 nm), vanadium in the +4 state can be effectively incorporated into the crystal lattice of TiO2 to tune the band gap energy by creating an impurity energy level (V5+/V4+) below the conduction band (2.1 eV) and retaining the anatase phase. In vanadium-incorporated TiO2 (V/TiO2), V4+ is a good dopant candidate as it can increase the lifetime of the charge carrier and reduce the electron–hole recombination rate, which results in high antibacterial activity under visible light irradiation. The present study explores the V/TiO2-based hot-dip zinc coating with enhanced electrochemical properties and long-term stability for combating biocorrosion. All the composites and the coatings are characterized by different techniques, including X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray analysis, confocal laser scanning microscopy, optical surface profilometry, and X-ray photoelectron spectroscopy. The biofilm formation assay and the cell viability assay reveal that the tuned composition of the V/TiO2-based hot-dip zinc coating effectively kills the adherent bacteria and inhibits biofilm formation on the surface. The high-charge-transfer resistance (225.67, 223.63, and 242.35 Ω cm2) and the high-inhibition efficiency (92.24, 92.30, and 92.02%) of the tuned composition of the V/TiO2-based hot-dip zinc coating confirm its efficient and sustainable antibiocorrosion performance and long-term stability even after an exposure period of 21 days in different bacterial environments. With the inherent antibacterial properties and antibiocorrosion performance of the developed V/TiO2-based hot-dip zinc coating, the mild steel substrates can find potential application in different fields, including aquatic and marine environments.

Multifunctional rGO–ZnO Composite Coatings with Enhanced Mechanical, Anticorrosion, and Antibacterial Characteristics for Practical Applications

“…Furthermore, the bare-Zn coating infers a lower S ku (1.480 μm) value than the 0.3 wt %-RGZ (4.483 μm), and it indicates the presence of a significant number of acute protuberances on the surface of the composite coating. The sharp protuberances on the composite coating surface can minimize bacterial adhesion and biofilm formation as compared to that on the bare-Zn coating surface …”

“…The sharp protuberances on the composite coating surface can minimize bacterial adhesion and biofilm formation as compared to that on the bare-Zn coating surface. 51…”

BiVO4–TiO2 Composite-Based Zinc Phosphate Coating for High NIR Reflectance and Sustainable Energy-Saving Applications

“…Mild steel is the most frequently used metal in almost all industries, including electrical, construction, and automobile applications, because of its excellent mechanical properties, economic viability, sustainability, recyclability, and durability. − However, it readily undergoes corrosion, resulting in severe economic and ecological issues. Among the different approaches to safeguard steel from corrosion, hot dip galvanized coating is a cost-effective and straightforward method. − Hot-dip coating protects the metal from corrosion through both physical barrier effect and sacrificial anode effect, even if some damage or minor discontinuity is formed on the surface of the coating. − A suitable chemical conversion coating could be helpful to seal the coating defects and further augment the corrosion resistance of galvanized coatings .…”

“…Mild steel is the most frequently used metal in almost all industries, including electrical, construction, and automobile applications, because of its excellent mechanical properties, economic viability, sustainability, recyclability, and durability. − However, it readily undergoes corrosion, resulting in severe economic and ecological issues. Among the different approaches to safeguard steel from corrosion, hot dip galvanized coating is a cost-effective and straightforward method. − Hot-dip coating protects the metal from corrosion through both physical barrier effect and sacrificial anode effect, even if some damage or minor discontinuity is formed on the surface of the coating. − A suitable chemical conversion coating could be helpful to seal the coating defects and further augment the corrosion resistance of galvanized coatings . Among the different chemical conversion methods, phosphating is often applied on galvanized coatings. , The phosphate coating has many industrial applications because of its economic feasibility, excellent wear and corrosion resistance, speed of operation, and excellent adhesion and lubricative properties. , Supplementary addition of metals or metal oxides in the phosphating bath could significantly modify the coating’s microstructure and thereby enhance anticorrosion performance. , In this study, we developed a modified zinc phosphate coating on a hot-dip zinc-coated steel by incorporating a NIR reflective BiVO 4 –TiO 2 composite.…”