RESEARCH Fe 3 O 4 nanomaterials: synthesis, optical and electrochemical properties Amaini Chouchaine 1 & Salah Kouass 2 & Fathi Touati 3 & Noureddine Amdouni 1 & Hassouna Dhaouadi 3 Received: 26 March 2020 /Revised: 10 November 2020 /Accepted: 18 November 2020 # Australian Ceramic Society 2021 Abstract The magnetite Fe 3 O 4 nanoparticles were synthesized via the hydrothermal process in the presence of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) as surfactants. The obtained products were characterized by X-ray powder diffraction, transmission electron microscopy, and ultraviolet-visible absorption spectroscopy. The electrochemical study of these products as advanced electrodes for supercapacitors was done using cyclic voltammetry (CV) and galvanostatic charge/ discharge tests. The specific capacity values deduced from the cyclic voltammetry experiments were found to increase in the following order: Fe 3 O 4 /without surfactant (34 F g -1 ) < Fe 3 O 4 /CTAB (44 F g -1 < Fe 3 O 4 /SDS (63 F g -1 ). The latter exhibited a specific discharge capacitance of 60 F g -1 that remained stable after 500 charge/discharge cycles. The improved electrochemical performance of Fe 3 O 4 /SDS may be due to the particle size and shape effects. As a result of the enhanced electrochemical performance, Fe 3 O 4 /SDS hybrids could be regarded as a promising electrode for Li/Na-ion batteries and supercapacitors. Keywords Fe 3 O 4 nanoparticles . TEM . Cyclic voltammetry . Galvanostatic charge/discharge Introduction Environmental issues are at present the most important prob- lem worldwide, and for that reason, there is an important de- mand for clean, efficient, and sustainable sources of energy as well as efficient technologies for energy conversion and stor- age. In this regard, supercapacitors have attracted increasing attention due to their long life cycle, high power density, and ability to bridge the power/energy gap between batteries/fuel cells and traditional dielectric capacitors [1, 2]. The major challenge for the supercapacitor is the power density, the cy- clic stability, and whether it can be cost-effective. Several researchers have been interested in the synthesis of new ma- terials to meet the growing demand for electrochemical capac- itors. Metal transition oxides are considered promising mate- rials for their use as high-performance pseudo-capacitors [3–7]. For example, the electrode based on the IrO 2 + Co 3 O 4 (30:70 mol%) composition has been found to perform as a superior electrode in electrochemical capacitor applications with a specific capacitance. The large capacitance exhibited by this system arises from a combination of the double layer capacitance and pseudo-capacitance associated with surface redox-type reactions [8]. The enhanced performance of the mesoporous NiO nano-flake arrays is mainly due to its hier- archical pore system [9]. The pine needle b-Co(OH) 2 /NF is characterized by the low charge-transfer resistance, high spe- cific capacitance, and excellent cycle stability [10]. The RuO 2 - Ag 2 O composite nanowires provide the high pseudo- capacitance and excellent high-rate performance [11, 12]. The mentioned metal oxides are too expensive for commercial purposes; however, the search for appropriate and cheap ma- terials still continues. With this purpose in mind, iron oxides have been identified as a low-cost and potentially environ- mentally friendly material. Among the iron oxides, magnetite (Fe 3 O 4 ) is considered as a supercapacitor material [9, 10]. The studies of Wu et al. [11] have shown that Fe 3 O 4 powders synthesized by the electro-coagulation and reflux method * Salah Kouass koissa2000@yahoo.fr 1 Laboratoire de Caractérisation Applications et Modélisation de matériaux, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis, Tunisia 2 Laboratoire MatériauxUtiles, Institut National de Recherche et d’Analyse Physico-chimique (INRAP), Sidi Thabet, 2020 Tunis, Tunisia 3 Laboratoire Matériaux Traitement et Analyse, Institut National de Recherche et d’AnalysePhysico-chimique (INRAP), Sidi Thabet, 2020 Tunis, Tunisia https://doi.org/10.1007/s41779-020-00544-3 / Published online: 7 January 2021 Journal of the Australian Ceramic Society (2021) 57:469–477