Ngnintedem Yonti Cedrik

Title : Green synthesis using palm kernel oil of Fe-doped Co3O4 nanoparticles and structural characterization

Abstract:

There is an increased interest in efficient green chemistry because it involves clean technology and is environmentally friendly/benign, economic and simple. In this study, a bio-derived precipitating agent/ligand, palm kernel oil, has been used as an alternative route for the green synthesis of nanoparticles of Iron-doped cobalt oxide (Fe- Co₃O₄) via the co-precipitation reaction. The palm oil was extracted from dried palm kernel seeds by crushing, squeezing and filtration. The reaction of the palm kernel oil with potassium hydroxide, under reflux, yielded a solution containing a mixture of potassium carboxylate and excess hydroxide ions, irrespective of the length of saponification. After neutralization of the as-obtained solution with nitric acid, an aqueous solution containing of iron and cobalt ions was added to yield the desired metallo-organic precursors, iron cobalt carboxylate. Characterization of the precursors by Fourrier Transform Infrared (FTIR) attests of the presence of the entire organic groups as expected while gas chromatography (GC) gives the profile of carboxylate group in the proportion predicted by the literature and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) confirms that the metallic ratios are as expected. The thermal decomposition of the precursors was monitored by thermogravimetry (TG) between 400 °C and 600 °C. The Analysis of the decomposition products by XRD, EDX, TEM and ToF-SIMS, confirmed  the formation of cobalt iron oxide  nanoparticles (Co_(1-x)Fe_x)₃O₄ for x≤0,2 and a nanocomposite material Co_(1-x)Fe_x)₃O₄/Fe₃O₄ for x≥0,2, with size between 22 and 9 nm. XRD suggests that there is only one spinel phase while ToF-SIMS provides a direct evidence of the progressive substitution of cobalt by iron in the Co₃O₄ crystal structure for x≤0,2.

Audience take-away:

• The audience will learn similitude between synthetic and natural O-donor ligands.
• They will learn how to use all vegetable oil as ligand for the synthesis of simple and mixed metal oxide nanoparticles.
• The audience will learn the importance of green synthesis in modern functional materials
• The audience can also learn on the valorisation of some Cameroonian natural sources.

Biography:

Cedrik Ngnintedem Yonti studied Chemistry at the University of Yaoundé I, Cameroon and graduated as  MS in 2010. He joined the team of Prof John Lambi Ngolui expert in the synthesis of nanoparticles, Cameroon and the team of Prof Arnaud Delcorte expert in Time of Flight Secondary Ions Spectroscopy (ToF-SIMS), Belgium, as Ph. D student in 2018. He is currently working on the synthesis of metal oxide nanoparticles using natural ligand coming from plants with the precipitation method.