Excellent antimicrobial and photocatalytic performance of C/GO/TiO2/Ag and C/TiO2/Ag hybrid nanocomposite beds against waterborne microorganisms

Abstract

Microbiologically contaminated water is a major health hazard worldwide. Where state-of-the-art solutions fail, nanomaterials come to the rescue with their multitasking features. Our study reports an excellent dual-mode action of novel hybrid nanocomposite filtration beds that combine antimicrobial with photocatalytic features. The activated carbon (C) was used as a substrate for in situ surface decoration with graphene oxide (GO) and bioactive TiO2/Ag nanocomposite particles (NCP) via a zero-waste one-pot sol-gel approach. Obtained C/GO/NCP and C/NCP hybrid nanocomposites were extensively evaluated for their morphology, structure, physicochemical and optical properties. The ability to decompose model methylene blue (MB) dye revealed their high photocatalytic efficiency. Further studies have shown the high potential of carbon-supported nanocomposites in eliminating model and waterborne bacteria cells under static and close-to-real dynamic filtration conditions. After filtration, hybrid nanocomposites eliminated up to 100% of accumulated bacteria cells, which confirmed their self-purifying potential. Finally, we recovered the beneficial properties of developed nanocomposites with low-temperature regeneration. Collectively, we proved the possibility of obtaining nanocomposite filtration beds with high potential in eliminating microbiological contamination, self-disinfection ability, and the possibility of recycling with minimal maintenance effort. Our study brings nanotechnology much closer to practical application in the water maintenance industry.