Synthesis, characterization and correlation studies on the Ni–Zn–Mn ferrite as a photocatalyst

Abstract Samples of Ni 0.3 Zn 0.7− x Mn x Fe 2 O 4 ( x = 0, 0.15, 0.25, 0.35, 0.45, 0.55) nanoparticles (NPs) were synthesized by auto-combustion flash method. These ferrites were used as catalysts for photodegradation of methylene blue (MB) dye utilizing visible light energy. Structural analysis was carried out using the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, while nanoparticle dimensions were elucidated through transmission electron microscopy (TEM). The magnetic and optical behaviours were unveiled via vibrating sample magnetometer and UV–VIS spectroscopy, respectively. The XRD outcomes established the presence of a cubic spinel-type structure for the studied ferrite samples. The FTIR spectra unveiled two absorption characteristic bands of the spinel ferrite. TEM images revealed nanoscale dimensions of ferrite NPs with the range from 21.1 to 51.8 nm. The optical features exhibited an indirect band gap energy spanning from 4.25 to 4.36 eV. Magnetization behaviour displayed a sinusoidal trend corresponding to varying Mn concentrations. The ferrite NPs catalyst (10 mg) yield photodegradation efficiency ranged from 22.8 to 33.9% for 100 ml MB dye solution after 120 min of light irradiation. The effects of dye concentration and catalyst dose on the degradation efficiency were examined using the Ni 0.3 Zn 0.35 Mn 0.35 Fe 2 O 4 catalyst with highest degradation (= 33.9%). On the other hand, the dependence of the degradation efficiency on the structure, morphological, magnetic and optical properties of the photocatalyst was investigated. The findings of this study underscore the potential of the prepared ferrite nanoparticles for advanced applications in environmental restoration. Graphical abstract