Controlled Formation of Hematite-Magnetite Nanoparticles by a Biosynthesis Method and Its Photocatalytic Removal Potential Against Methyl Orange Dye

It is presented a green synthesis method to obtain hematite (or magnetite) as a function of the concentration of Coffea arabica L extract mixed with a single iron salt precursor. The crystal structure, microstructural and phase formation of the iron oxide nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, Mossbauer spectroscopy and DC magnetometry. The particle sizes of the obtained nanoparticles are of the order of 5 nm. Optical properties were studied with UV-Vis spectroscopy from which a band gap energy of E-g = 3.09 eV for hematite and E-g = 3.23 eV for magnetite were deduced. The photocatalytic activity of the synthesized nanoparticles was tested by degradation of methyl orange dye under UV radiation, showing their potential application in wastewater treatment.

Automated summary

A green synthesis method using Coffea arabica L extract and iron salt precursor was used to obtain iron oxide nanoparticles, which showed potential application in wastewater treatment.