Synthesis and antimicrobial behaviour of NiO/Ag-based material

The main objective of the present work is the green synthesis of NiO and Ag nanoparticles using the leaf extract of Azadirachta indica and the development of NiO/Ag-based nanocomposites via an ultrasonic process. The synthesised NiO/Ag was characterised using different analytical methods and used as an antimicrobial agent against different bacterial and fungal strains. The antimicrobial study was done using the well diffusion method. The FTIR study indicated the presence of O-H, C-H (methylene or methyl), C--O, O-H, and Ni-Ag, Ag-O, or Ni-O bonds on the surface of NiO/Ag. The XRD peaks of NiO/Ag were found to be 31.60 (103), 37.30 (111), 38.10 (111), 43.40 (200), 62.90 (220), 76.50 (008), 77.50 (311), and 79.50 (222), respectively. The maximum zones of inhibition were found to be 21.6 (+/- 0.71), 21.2 (+/- 0.69), 17.9 (+/- 0.39), 13.3 (+/- 0.81), and 12.3 (+/- 0.38) mm against Escherichia coli, Staphylococcus aureus, Salmonella enterica, Candida albicans, and Aspergillus niger after incubation periods. On the basis of these findings, we can conclude that NiO/Ag is a potent antimicrobial agent against a variety of bacterial and fungal species.