Abstract Nickel-incorporated vanadium pentoxide (V 2-2x Ni 3x O 5-δ, 0. 03 ≤ x ≤ 0. 06) microparticles were synthesized and structurally characterized, revealing a biphasic composition dominated by orthorhombic V 2 O 5 with Pmmn space group and a minor triclinic NiV 2 O 6 phase with cap P 1 ̅ P1 space group, as confirmed by Rietveld refinement. With increasing Ni content, the orthorhombic lattice parameters expanded due to ionic substitution. At the same time, the emergence of a distinct peak at 2θ = 23. 57° indicated the onset of NiV 2 O 6 phase formation, reaching 12. 2 wt% at x = 0. 05 and signifying a solubility-driven structural transition. X-ray photoelectron spectroscopy (XPS) revealed the presence of mixed oxidation states of Ni (Ni 1+, Ni 2+, Ni 3+) and V (V 4+, V 5+), along with a chemically diverse oxygen environment comprising lattice oxygen, surface hydroxyls, and adsorbed oxygen species. The as-prepared compounds exhibited potent and broad-spectrum antimicrobial activity, demonstrating significant inhibition against the Gram-negative bacterium Pseudomonas aeruginosa and effective activity against the Gram-positive bacteria Staphylococcus aureus and Escherichia coli. The antimicrobial mechanism is attributed to a synergistic interplay of reactive oxygen species (ROS) generation, redox-mediated metal ion toxicity, and physical disruption of microbial membranes. Moreover, the increasing molar fraction of Ni enhanced antimicrobial efficacy, supporting a concentration-dependent increase in ROS production and microbial interaction.
Sabna et al. (Mon,) studied this question.