Facile On-Substrate Fabrication of Silver Coordination Polymer Nanowires for Sustainable and Efficient Water Disinfection

Abstract

Silver, as the oldest antibacterial material, has been almost replaced by other alternatives for its insufficient activity or potential side-effects on the ecosystem due to the over-release of Ag ions (Ag⁺). Herein, a facile and general strategy is developed to on-substrate fabricate silver coordination polymer nanowire arrays (Ag CPN) by simply immersing Ag-containing substrates into cationic surfactant solution at room temperature. Such a Ag CPN not only provides high-surface-area nano-biointerfaces for destroying microorganisms via physicomechanical interactions but also acts as a safe Ag⁺ reservoir, steadily releasing Ag⁺ at a relatively high but safe level (∼40 ppb, but lower than the safe level of 100 ppb). Taking advantage of physicomechanical and chemical effects together, the on-substrate fabricated Ag CPN allows Ag substrates or Ag-coated disposable substrates for efficient and sustainable bacterial disinfection. As a demonstration, the modified silver net shows ∼100% antibacterial activity when the bacterial water with a 1.0 × 10⁶ CFU mL^–1 of E. coli flows through in 4.0 m³ h^–1 m^–2 fluxes. By coating a silver film onto a wide range of cheap or disposable substrates, the present strategy opens up opportunities for reviving ancient silver materials for affordable and recoverable antibacterial applications such as water disinfection.