The effect of thermal treatment on the antimicrobial properties of silver nanoparticles on the silica surface

Abstract

This study investigates the influence of thermal treatment on the antimicrobial properties of silver nanoparticles NPs Ag⁰ deposited on a macroporous Silochrome. The research focuses on the morphological and distributional changes of the nanoparticles under elevated temperatures and their subsequent impact on antibacterial activity. The results demonstrate that increasing the treatment temperature reduces nanoparticle size and enhances their distribution on the silica surface, significantly improving antimicrobial efficacy. The immobilization of Ag⁺ cations from a solution and the incorporation of reduced NPs Ag⁰ onto the silica surface resulted in a homogeneous distribution of nanoparticles around mesopores and imparted antibacterial properties. The critical role of the acid–base centers of SiO₂ in the antibacterial activity of SiO₂/Ag⁰ nanostructures was established, and conditions for optimizing this activity were determined by altering the size and localization of NPs Ag⁰ through thermal treatment at 500 °C, which reduced the minimum inhibitory concentration by six-to-seven times. These findings highlight the potential of thermal treatment as a viable method for optimizing the antimicrobial performance of SiO₂-based nanocomposites.