Insights into efficient bacterial inactivation over nano Ag/graphdiyne: dual activation of molecular oxygen and water molecules

Abstract

The dual activation mechanism of molecular oxygen (O₂) and water (H₂O) in the local structure of catalysts has not been elucidated yet. Herein, we report a strategy for manufacturing fully exposed Ag₄ sites in nano silver/graphdiyne (Ag/GDY) composites for activating O₂ and H₂O. The synthesized nano Ag was uniformly anchored on the surface of GDY without any surfactant added, with an average particle size of 2.5 nm. The unique sp-hybrid C and triangular pore structure of GDY not only regulate the stable geometric structure of nano Ag, but also enhance the adsorption ability of Ag₄ sites for O₂ and H₂O molecules in nano Ag/GDY. Electron spin resonance spectroscopy and density functional theory calculation results proved that O₂ is more favorable to synergistically promote the activation of H₂O to generate reactive ·O₂⁻ and ·OH radicals on the nano Ag/GDY surfaces, leading to outstanding antibacterial activity. This work provides a simple strategy for the preparation of stable nano Ag and proposes to improve the catalytic oxidation activity by adjusting the local electronic structure of catalysts to activate O₂ and H₂O.