Coordination driven vanadium/L-cysteine hybrid conversion film to improve the corrosion resistance of copper.

Vanadium/L-cysteine (V/L-cys) hybrid films with favorable anti-corrosion performance were fabricated on copper substrate based on the coordination between Vanadium and L-cys. The characteristic adsorption of sulfhydryl groups (-SH) in L-cys on copper acts as a bridge for film formation, while the coordination between VO2+ ions and –COOH or NH 2 in L-cys repairs defects and enhances the density of film. The EIS results indicated that the corrosion protection efficiency of V/L-cys film was 99.6 %, which was much higher than that of single L-cys film (91.1 %). Moreover, the immersion test exhibited that V/L-cys film was capable of enduring 300 min of immersion in a 3.5 % NaCl solution, whereas L-cys film could only withstand 60 min of immersion. The durability of V/L-cys film showed a significantly higher level than that of L-cys film. [Display omitted] • A hybrid conversion film was fabricated on the copper surface. • Coordination between VO2+ and L-cys improve the performances of hybrid film. • The corrosion protection efficiency of V/L-cys film was 99.6 %. • The V/L-cys film exhibited excellent durability in NaCl solution. [ABSTRACT FROM AUTHOR]