Structural, Optical, Photocatalytic, and antimicrobial attributes of niobium substituted copper nanoferrites

•Niobium substituted copper nanoferrites were derived from the solution combustion method.•The maximum photodegradation of rhodamine dye occurred for N7CFO nanoparticles is 66.3 % in 90 min UV-light irradiation at neutral pH and 87.2 % at pH 4.5.•Sensor investigations for lead by N7CFO electrode in 0.1 M KCl medium demonstrate that the N7CFO NP is a suitable sensor.•The obtained N7CFO nanoferrite effectively remedied the gram-negative Pseudomonas bacterium.