Effect of PEG/CTAB on capacitive performance of α-Fe2O3-CuO nanocomposite electrode

In this study, α-Fe 2 O 3 -CuO nanocomposite thin films were successfully deposited on the glass and ITO substrates by a sol-gel process with the presence of cetyltrimethylammonium bromide (CTAB) surfactant and polyethylene glycol 6000 (PEG) with the focus on the physical and electrochemical properties. The structure, morphology, electrochemical, magnetic, and wettability properties of the α-Fe 2 O 3 -CuO manipulated with PEG and CTAB, were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), potentiostat/galvanostat analyses (CV, EIS, and GCD), vibrating-sample magnetometry (VSM) and contact angle (CA) measurements. All nanocomposite samples have a mixture of two phases, the hematite phase with the rhombohedral structure for iron oxide and the tenorite phase with the monoclinic structure for copper oxide. It is observed that the presence of CTAB and PEG causes a change in morphology without any phase change in structure. The presence of PEG and CTAB also leads to the creation of rise shape grain and circular holes in the surface morphology of the iron oxide and copper oxide nanocomposite, respectively. The average surface roughness which is increased by the addition of PEG and CTAB leads to an increase in hydrophilic property of the samples. The investigation showed that the addition of polymers substantially improved the electrochemical properties of iron-copper oxide thin film, so that the α-Fe 2 O 3 -CuO electrode with PEG and CTAB showed the maximum specific capacitance (112 mF/cm 2 ) among all the samples. The magnetic analysis represented that CTAB and PEG addition improved the saturation magnetization with ferromagnetic behavior at room temperature. Graphical Abstract Highlights PEG/CTAB/α-Fe2O3-CuO thin films were deposited on the substrates by sol-gel method. Incorporating PEG/ CTAB in α-Fe2O3-CuO nanocomposite leads to change morphology. PEG/CTAB/α-Fe2O3-CuO thin films with a rough surface showed good hydrophilicity. The specific capacitance of PEG/CTAB/α-Fe2O3-CuO electrodes is five times higher.