Gold-modified ZnO nanocomposites for photo-Fenton-like catalysis of Escherichia coli disinfection

•Au/ZnO nanocomposites were synthesized under relatively mild conditions.•Visible light absorption was enhanced via the surface plasmon resonance effect of gold nanoparticles.•E. coli can be effectively disinfected by Au/ZnO nanocomposites under photo and photo-Fenton catalysis.•Hydroxyl radicals were present under all catalysis progress. In this study, gold-modified zinc oxide (Au/ZnO) nanocomposites were fabricated using the solvothermal method. Structure, morphology, and components of Au/ZnO nanomaterials were investigated by XRD, TEM, and XPS analyses, respectively. Results of the UV–Vis analysis manifested a shifting of absorption to light of nanocomposites from visible towards red because of the incorporation of Au and its surface plasmon resonance. In addition, an antibacterial test demonstrated that as compared to pure ZnO and ZnO nanocomposites cooperated with other contents of Au, 1/101 Au/ZnO nanocomposites displayed the highest photocatalysis disinfection activity to Escherichia coli cells. Fenton-like and photo-Fenton-like reactions were executed to further explore the effect of 1/101 Au/ZnO nanocomposites, in which the ESR results revealed the producing of hydroxyl radicals that are considered as one of the dominants to antibacterial activity during photocatalytic disinfection process.