An intelligent self-defensive coating based on sulfide ion responsive nanocontainers for suppression of microbiologically influenced corrosion induced by sulfate reducing bacteria

Highlights: • Zeolitic imidazolate framework-8 is selected as capsulation nanovalves. • Nanovalves are capped on hollow mesoporous silica nanoparticles to block biocide. • Sulfide ion responsive release of biocides from nanocontainers is realized. • The coating with nanocontainers shows superior anti-adhesion ability. • The coating protects steel from corrosion induced by sulfate reducing bacteria. S^2―-responsive nanocontainers are constructed by assembling zeolitic imidazolate framework-8 onto hollow mesoporous silica nanoparticles. Spontaneous leakage of incorporated biocides is nearly restrained and release initiates when S^2― is higher than 0.04 mM. Such nanocontainers can respond to S^2― fluctuation derived from microbiologically influenced corrosion (MIC) induced by sulfate reducing bacteria (SRB). The protective performance of coating with smart nanocontainers is evaluated in SRB environment. It demonstrates the intelligent coating exhibits the fewest bacterial settlement, highest impedance (3.31 × 10⁷ Ω cm²) and lowest corrosion current density (1.36 × 10⁻¹⁰ A cm⁻²) after 14-day immersion, revealing the optimal resistance to MIC.