Antibacterial activity of Cu2O and Ag co-modified rice grains-like ZnO nanocomposites

Abstract In this work, a series of Cu 2 O-Ag/ZnO, Cu 2 O/ZnO and Ag/ZnO nanocomposites with various compositions were prepared via a hydrothermal method followed by chemical modification, and their antibacterial performance was investigated in detail. X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy results confirmed that 31 nm Cu 2 O and 30 nm Ag nanoparticles are well-dispersed on 202 nm ZnO grains to form a Cu 2 O/ZnO and Ag/ZnO heterojunction, respectively. The bi-heterojuction structure in the Cu 2 O-Ag/ZnO provided a synergistic effect on antibacterial activity, and the (Cu 2 O) 0.04 Ag 0.06 ZnO 0.9 nanocomposites showed the highest antimicrobial activity of all samples with minimum inhibitory concentration and minimum bactericidal concentration against Escherichia coli and Staphylococcus aureus as low to 31.25 μg/mL, 250 μg/mL, 125 μg/mL and 500 μg/mL, respectively. This is the first report of the antibacterial activities of Cu 2 O and Ag co-modified ZnO nanocomposites.