Phytosynthesized Cu‐Doped Cerium Oxide Nanoparticles for Antibacterial Application

Herein, phytosynthesized copper doped cerium oxide nanoparticles (NPs) are synthesized and their application potential in antibacterial activity is investigated. The compensative effect of Cu 2+ occupying Ce 4+/ Ce 3+ site and redox conversion of Ce 4+ to Ce 3+ are found to facilitate the antibacterial activity of the doped NPs. The preliminary characterizations are done using X‐ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and energy‐dispersive analysis of X‐ray spectroscopy. The particle size distribution curves from field‐emission scanning data give the mean particle sizes to be ≈20.4, 19.9, and 18.8 nm, respectively, for pure, lightly doped, and heavily doped NPs. The transmission electron microscopy manifests tetra‐ and hexa‐shaped particles, indicating the presence of Ce 2 O 3 /Ce 1− x Cu x O 2 along with ceria in pure and lightly doped and an additional presence of CuO in the heavily doped. The X‐ray photoelectron spectra of Ce 3 d deconvolute to 10 peaks corresponding to Ce 3+ and Ce 4+ yielding Ce 3+ /Ce 4+ % ratio <1 and Cu 2 p and O 1 s spectra are fitted to assess variation in Cu% and oxygen vacancies with doping. The Cu‐doped CeO 2 samples show a commendable improvement over pure ceria, in the antibacterial activity against pathogenic bacteria Escherichia coli, Staphylococcus aureus , and Bacillus cereus .