Magnetic cobalt ferrite has wide spread applications, especially as catalyst for the conversion of alkenes to related aldehydes. Despite several studies found in the literature concerning the fabrication of cobalt ferrite, none has reported on gamma irradiation as a tool for the synthesis of submicrometer sized inverse spinel CoFe 2 O 4 . The actual investigation reports on the application of γ-irradiation method for the synthesis of superparamagnetic CoFe 2 O 4 , using metal salts precursors and organic reagents. The material fabrication occurs in two main steps as sofar described. The obtained powder was isolated after irradiation and was characterized using X-ray diffraction method, transmission electron microscopy, FT-IR spectroscopy, Raman spectroscopy, UV-visible measurements and vibrating sample magnetometer. Furthermore, the X-ray diffraction data revealed the presence of a reverse spinel structure. The magnetic properties of the fabricated powder exhibited the measured lower coercivity and remanence, demonstrating that the spinel powders are made of superparamagnetic particles and finally, to gain information about the photocatalytic properties of the synthetized material, the room temperature recorded optical measurements for different samples proved that these powder materials may probably exhibit new opportunities which could improve their high photocatalytic efficiency under visible light. The prepared materials could be used as potetentiel candididates for the oxidation of organics compounds.

Nowadays many researchers are focused on the sytnhesis of nanoscale tricobalt tetraoxide (Co3O4) particles, owing to their unique properties. These particles have indeed many potential technological applications. The present investigation deals with the fabrication of this spinel oxide: it was successfully synthesized through a friendly environmental method, using cobalt (II) chloride as cobalt precursor and aqueous extract of Moringa oleifera leaves. The latter contains alkaloids as a base source while flavonoids present in the leaves acted as capping agent to prevent the particles agglomeration. Alkaloids present in the leaves were hydrolyzed in water and consequently, hydroxilated Co2+ leads to the formation of Co3O4 powder via calcination. The electronic transmission microscopy has revealed the single crystalline nanorods morphology of the synthetised materials. These nanorods are about several hundred nanometers long and several tens of nanometers in diameter. The bulk Co3O4 is known to be antiferromagnetic, the vibrating sample magnetometer data (at room temperature) of the prepared powder exhibited the lower coercivity and remanence, signaling that the produced spinel was pure and was constituted of superparamagnetic particles made of Co3O4. The UV–visible spectrum exhibited a photoluminescence peak in the visible light range positioned at about 538nm, suggesting this spinel as a visible light emitting material and as photocatalyst under visible light.

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