Antibacterial properties of metal nanoparticles–incorporated activated carbon composites produced from waste biomass precursor

Abstract

Activated carbon-based composite materials, together with the well known antibacterial activity of metal nanoparticles, urged the performance of this study to prepare new antibacterial materials with antimicrobial activity, as an important step in fighting pathogenic organisms. Activated carbon derived from a waste source - almond shells - were combined with metal (Ag, Cu, Mg) nanoparticles, in order to obtain metal composite with desirable characteristics. The composites were obtained using one-step high-temperature hydro-pyrolysis and further impregnation of the metal from water solution. Investigation of the structure, chemical composition and morphology of obtained composites was carried out by scanning electron microscopy, XRD, XPS, elemental and BET analysis, before testing their antimicrobial activity. Strongest antibacterial effect against E. coli was observed when 10 % Cu Activated Carbon Composite (ACCCu) was used attaining 100 % reduction of microbial count even at the starting point. ACCAg, ACCMg and activated carbon only, demonstrated such effect after 24 h. Best results after treatment of S. aureus were achieved with ACCAg and ACCCu after 24 h.The results indicate that the antibacterial activity depends on the contact time, bacterial species, nature of the metal and metal concentration. The novel metal nanoparticles-incorporated activated carbon composites demonstrated very good antibacterial activity. The investigation provides novel materials with antibacterial properties for further development and potential application in hygiene devices.