Efficient self-cleaning and antibacterial ceramics with ultra-low doping and high exposure of silver

The secondary bacterial infection of COVID-19 is known to contribute significantly to mortality rates. Silver (Ag)-based antibacterial ceramics have emerged as a prominent solution for daily antibacterial applications, aiming to minimize the reliance on disinfectants while safeguarding human health. However, the fabrication of Ag-based antibacterial ceramics with low Ag content, high dispersion, and high exposure still faces challenges. In this work, an innovative method was proposed to doping Ag nanoparticles (Ag NPs) into glass ceramics (GC) via a "melt-freeze" method, then efficient and stable Ag-doped antibacterial ceramics (GC-xAg@BiOCl) were fabricated through facile in-situ HCl etching GC. Results indicate that the low Ag content (0.03 mol%) and high dispersion of Ag NPs are fully exposed and anchored on the surface, and constructed Schottky junction Ag/BiOCl contributed to antibacterial and photocatalytic activity. The degradation rates of norfloxacin and methylene blue by GC-0.25Ag@BiOCl can reach 71.0% and 55.3% under visible light irradiation, respectively. Moreover, The GC-0.25Ag@BiOCl exhibited significant antibacterial activity against Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus), with E.coli at 7.3 log₁₀ cfu/mL and S. aureus at 7.0 log₁₀ cfu/mL completely inactivated under visible light irradiation. Additionally, the antibacterial mechanism and charge transfer mechanism were explored.