Synergistic effect of morphology on the biocidal response of Ce-doped ZnO nanomaterial synthesized by facile autocombustion method

Effect of sintering and annealing on the morphology of zinc oxide (ZnO) and cerium-doped ZnO nanomaterials and their biocidal response was investigated. The autocombustion method was employed to prepare Ce-doped ZnO with cerium (Ce) concentrations of 0, 2, 4, 6, and 8 wt%. Subsequently, all the compositions were sintered at 800 ᴼ C in the air to develop desired crystalline phase. Half of the sintered material was further annealed at 900 ᴼ C in the air for 2 h. A wurtzite crystal structure was confirmed by X-ray diffraction, and an optical redshift was noticed upon dopping in the sintered and annealed specimens. Fourier transform infrared (FTIR) and scanning electron microscopic (SEM) analyses were carried out to determine functional groups and surface morphology, respectively. The biocidal response of sintered and annealed ZnO and Ce-doped ZnO against Bacillus meurellus, Escherichia coli, Acinetobacter rhizospherensis, and Bacillus subtillis were measured by the disc diffusion method and compared with penicillin as a standard antibiotic. Maximum efficiency was observed in the case of annealed 2% concentration of Ce in ZnO against all the selected bacteria in the form of inhibition zones of 34, 27, 40, and 40 mm for B. meurellus, E. coli, A. rhizospherensis, and B. subtillis, respectively, in 24 h. The obtained results highlight the morphological significance of Ce-doped ZnO nanomaterial in the antibacterial activity.