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

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.