Effect of ZnO/Ag Nanocomposites Against Anionic and Cationic Dyes as Photocatalysts and Antibacterial Agents

Engineering efficient, strong and cost-effective nanoparticles with strong inhibitory activities are the growing need at present. Using the strategies of doping, Zinc oxide/Silver nanocomposites (ZnO/Ag NCs) namely 0.9 M ZnO: 0.1 M Ag, 0.7 M ZnO: 0.3 M Ag and 0.5 M ZnO: 0.5 M Ag were synthesized hydrothermally. The average crystallite sizes for the ZnO/Ag NCs were 31 nm, 29 nm and 23 nm. The band gap energy (E g ) for the ZnO/Ag NCs was estimated to be 3.09 eV, 3.12 eV and 3.18 eV using Tauc’s plot. Grain-like morphological images was observed in the Scanning Electron Microscopy (SEM), which helps in effective promotion of degrading methyl orange (MO), methylene blue (MB) and crystal violet (CV) under visible light irradiation with a rate constant of 5 × 10 –3 /min, 16.6 × 10 –3 /min and 4 × 10 –3 /min respectively. This superior photocatalytic decomposition of dye are ascribed to smaller particle size, high surface area, the ability to absorb visible light and the efficient charge separation associated with the synergetic effects of appropriate amounts of ZnO and Ag in the prepared samples. In addition, the antibacterial efficacy of the NCs is observed as 90 and 100% for 75 μl. These hydrothermally synthesized synergistic NCs can be designed for large-scale fabrication of NC materials for potential applications in photocatalytic and antibacterial activity.