Carbonaceous MnFe2O4 nano-adsorbent: Synthesis, characterisation and investigations on chromium (VI) ions removal efficiency from aqueous solution

Carbonaceous manganese ferrite nanoparticles were prepared at relatively lower temperature using co-precipitation method followed by a single-step pyrolysis process. Synthesized nanoparticles were further characterized by different spectroscopic and microscopic techniques. The X-ray Diffraction (XRD) study confirmed the formation of single phase cubic spinel structure and the presence of graphitic carbon of plane (002) and the size of the prepared nanostructure was of 36 nm. With the confirmation of formation of carbonaceous MnFe2O4 and the number of oxygen functionalities such as hydroxyl and C-O-C groups emanating from the carbon matrix, as confirmed by the Fourier Transform Infrared (FT-IR) studies motivated their usage to remove Cr (VI) ions from aqueous solution. The study parameters such as influence of time, adsorbent dosage, concentration and pH are explored along with isotherm and kinetic studies. The carbonaceous nanoparticle was able to remove Cr (VI) by ∼80% at native pH, with a carbonaceous MnFe2O4 dose of 10 mg, and the initial concentration 10 ppm of contaminant with the contact time, 80 min and is found promising for the practical applications.