Insight into the structural, magnetic and fluoride (F−1) adsorption properties of copper–manganese ferrite (Cu0·5Mn0·5Fe2O4) and Azadirachta Indica composites synthesized through hydrothermal method

Fluoride contamination of the aquatic environment due to both natural and man-made activity is one of the most pressing concerns affecting the world today. In the current research, copper-doped manganese ferrites (Cu 0 · 5 Mn 0 · 5 Fe 2 O 4 ) with Azadirachta indica (neem leaves) composites were prepared employing a hydrothermal approach for eliminating fluoride ions from drinking water . The XRD verified single-phase spinal structure, and it was observed that increase of the neem leaves contents altered the lattice parameter from 8.58 A ˙ to 8.54 A ˙ . In SEM micrographs, the aggregated and different-sized nanocomposites were observed. The Raman spectra demonstrated that for pure copper manganese ferrite, the Raman mode is approximately 600 cm −1 , whereas the presence of neem leaf extract was detected at Raman mode between 1200 and 1300 cm −1 . For copper manganese ferrite, the FTIR spectra indicate that the absorption bands of octahedral and tetrahedral site are around 543 cm −1 and 649 cm −1 , respectively. The band gap was calculated using UV–visible spectroscopy which dropped from 1.9 eV to 1.7 eV and 1.5 eV because of the insertion of neem leaves extract in copper manganese ferrites. The inclusion of neem leaves extract in Cu 0 · 5 Mn 0 · 5 Fe 2 O 4 results in decreasing of both coercivity (H c ) and saturation magnetization (M s ), as verified by the M−H loops. Fluoride removal was carried out for composite sample (10 ml neem leaves extract) at a range of pH levels, from 3 to 11. To determine the precise mechanism of the interactions, two models of kinetics, the pseudo-first order (PFO) and the pseudo-second order (PSO) models, were applied to fit the sorption data. The experimental data shows better fitting for PSO model thereby confirming that the dominant adsorption mechanism is chemisorption . The synthesized composite exhibits maximum adsorption and reaches WHO limit only after 3 h showing a great potential of these materials in real time adsorption of fluoride polluted water. • Copper-doped manganese ferrites with Azadirachta indica composites were prepared. • In SEM micrographs, the aggregated and different-sized nanocomposites were observed. • The pseudo-first order and the pseudo-second order models, were applied to fit the sorption data. • The experimental data shows better fitting for PSO model thereby confirming the chemisorption. • The synthesized composite exhibits maximum adsorption and reaches WHO limit only after 3h.