Composite Fe(3)O(4)-MXene-Carbon Nanotube Electrodes for Supercapacitors Prepared Using the New Colloidal Method

MXenes, such as Ti(3)C(2)T(x), are promising materials for electrodes of supercapacitors (SCs). Colloidal techniques have potential for the fabrication of advanced Ti(3)C(2)T(x) composites with high areal capacitance (C(S)). This paper reports the fabrication of Ti(3)C(2)T(X)-Fe(3)O(4)-multiwalled carbon nanotube (CNT) electrodes, which show C(S) of 5.52 F cm(−2) in the negative potential range in 0.5 M Na(2)SO(4) electrolyte. Good capacitive performance is achieved at a mass loading of 35 mg cm(−2) due to the use of Celestine blue (CB) as a co-dispersant for individual materials. The mechanisms of CB adsorption on Ti(3)C(2)T(X), Fe(3)O(4), and CNTs and their electrostatic co-dispersion are discussed. The comparison of the capacitive behavior of Ti(3)C(2)T(X)-Fe(3)O(4)-CNT electrodes with Ti(3)C(2)T(X)-CNT and Fe(3)O(4)-CNT electrodes for the same active mass, electrode thickness and CNT content reveals a synergistic effect of the individual capacitive materials, which is observed due to the use of CB. The high C(S) of Ti(3)C(2)T(X)-Fe(3)O(4)-CNT composites makes them promising materials for application in negative electrodes of asymmetric SC devices.