Novel Mo: CoFe2O4 nanoparticles combustion synthesis for opto-magneto-electrochemical applications: A systematic analysis

In current work, various concentrations (0.0 wt%, 0.10 wt%, 0.25 wt%, 0.50 %,0.75 wt%, and 1 wt%) of Molybdenum (Mo) - doped cobalt ferrite (CFO) nanoparticles (Mo:CFO NPs) were synthesized using the flash combustion approach. The structural analysis of the prepared Mo:CFO was examined by the XRD patterns, and the obtained crystallite size 48.64, 46.72, 22.81, 21.05, 18.03, and 19.31 nm for 0.0 wt%, 0.10 wt%, 0.25 wt%, 0.50 wt%, 0.75 wt%, and 1 wt% Mo:CFO NPs, respectively. The presence of stoichiometry and homogeneity of the prepared Mo:CFO NPs was confirmed by the EDX analysis. The five phonon modes of the prepared Mo:CFO NPs were recorded by FT-Raman spectra, and the phonon modes were observed around 220, 312, 479, 624, and 685 cm⁻¹ that corresponded o T_2g(2), E_g, T_2g(1), A_1g(2), and A_1g(1) symmetries, respectively. The grain sizes of the pure CFO and Mo:CFO NPs were evaluated using the images of scanning electron microscopy (SEM) and obtained in the range of 39–61 nm, respectively. The presence of valence states Co (2p), Fe (2p), O (1 s), and Mo (3d) in the prepared 1 wt% Mo:CFO NPs were examined by XPS spectra. The particle sizes ∼26.4 nm and ∼ 16.7 nm were obtained for pure CFO and 1 wt% Mo:CFO NPs using lognormal function fitting. The emission peaks at 445 ± 3, 521 ± 3, and 620 ± 2 nm in the PL spectra were observed by PL spectroscopy. The decrease in saturation magnetization Ms. (70.80–66.54 emu/g) and reduced remanent magnetization Mr. (24.22–18.64 emu/g) of prepared Mo: CFO NPs was observed in the MH analysis by SQUID analysis. The electrochemical study of Mo: CFO NPs (0.0 %, 0.25 %, 0.50 %, and 1.0 %) was done in a three-electrode assembly cell. The capacitance of values 650.0 Fg⁻¹, 800.0 Fg^-1, and 810.0 Fg⁻¹ for pure CFO, 0.25 % Mo: CFO, and 0.50 % Mo: CFO were recorded in electrochemical analysis. The highest capacitance of 840.0 Fg⁻¹ was observed for the electrode with 1.0 % Mo: CFO NPs. It was analyzed that the increase in CFO electrodes enhances their performance, and therefore, it can be utilized for multifunctional devices.