The aim of this study was to describe the modification of the bioactivity of Al2O3‐noble metal (Me = Ag, Au, or Pd) composite nanoparticles by the addition of graphene oxide and the formation of a RGO/Al2O3‐Me nanocomposite system. The nanocomposite flakes and Al2O3‐Me composite nanoparticles were widely characterized. The antibacterial effect was observed only for Al2O3‐Ag composite nanoparticles and RGO/Al2O3‐Ag nanocomposite flakes, while, in the case of RGO/Al2O3‐Ag, a more evident antibacterial effect against Staphylococcus aureus bacteria was observed compared with Al2O3‐Ag. In the case of other noble metals (Au, Pd), a slight growth‐stimulating effect was revealed for particular bacterial strains.

This study aims to describe the influence of adding graphene oxide to TiO2-noble metal (Me=Ag, Au or Pd) composite nanoparticles on their bioactivity (formation of RGO/TiO2-Me nanocomposite system). The obtained nanocomposite flakes and reference TiO2-Me nanoparticles were characterized using SEM, HRTEM and XPS spectroscopy, N2 sorption analysis and helium pycnometer. The analysis of the antibacterial properties of synthesized nanocomposites revealed a growth inhibiting effect of TiO2-Ag particles on gram positive bacteria such as: Staphylococcus aureus, Sarcina lutea and Bacillus subtilis. In the case of nanocomposite flakes containing RGO the visible changes in bacteriostatic properties were observed, including unexpected reversal of the antimicrobial activity of silver-containing nanoparticles into the stimulation of growth of applied bacterial strains. The stimulation of growth was not observed for TiO2-Au and Pd nanoparticles deposited on the surface of RGO.

Achieving both effective and sustainable water decontamination technology requires development of a universal filtration solution.