Fe₂O₃/Reduced Graphene Oxide/Fe₃O₄ Composite in Situ Grown on Fe Foil for High-Performance Supercapacitors

A Fe₂O₃/reduced graphene oxide (RGO)/Fe₃O₄ nanocomposite in situ grown on Fe foil was synthesized via a simple one-step hydrothermal growth process, where the iron foil served as support, reductant of graphene oxide, Fe source of Fe₃O₄, and also the current collector of the electrode. When it directly acted as the electrode of a supercapacitor, as-synthesized Fe₂O₃/RGO/Fe₃O₄@Fe exhibited excellent electrochemical performance with a high capability of 337.5 mF/cm² at 20 mA/cm² and a superior cyclability with 2.3% capacity loss from the 600th to the 2000th cycle

Two-Dimensional Titanium Carbide/RGO Composite for High-Performance Supercapacitors

Ti₃C₂T_<i>x</i>, a 2D titanium carbide in the MXenes family, is obtained from Ti₃AlC₂ through selective etching of the Al layer. Due to its good conductivity and high volumetric capacitance, Ti₃C₂T_<i>x</i> is regarded as a promising candidate for supercapacitors. In this paper, the fabrication of Ti₃C₂T_<i>x</i>/RGO composites with different proportions of Ti₃C₂T_<i>x</i> and RGO is reported, in which RGO acts as a conductive “bridge” to connect different Ti₃C₂T_<i>x</i> blocks and a matrix to alleviate the volume change during charge/discharge process. In addition, RGO nanosheets can serve as a second nanoscale current collector and support as well for the electrode. The electrochemical performance of the as-fabricated Ti₃C₂T_<i>x</i>/RGO electrodes, characterized by CV, GCD, and EIS, are also reported. A highest specific capacitance (<i>C</i>_s) of 154.3 F/g at 2 A/g is obtained at the Ti₃C₂T_<i>x</i>: RGO weight ratio of 7:1 combined with an outstanding capacity retention (124.7 F/g) after 6000 cycles at 4 A/g

One-Step Hydrothermal Synthesis of 3D Petal-like Co₉S₈/RGO/Ni₃S₂ Composite on Nickel Foam for High-Performance Supercapacitors

Co₉S₈, Ni₃S₂, and reduced graphene oxide (RGO) were combined to construct a graphene composite with two mixed metal sulfide components. Co₉S₈/RGO/Ni₃S₂ composite films were hydrothermal-assisted synthesized on nickel foam (NF) by using a modified “active metal substrate” route in which nickel foam acted as both a substrate and Ni source for composite films. It is found that the Co₉S₈/RGO/Ni₃S₂/NF electrode exhibits superior capacitive performance with high capability (13.53 F cm^–2 at 20 mA cm^–2, i.e., 2611.9 F g^–1 at 3.9 A g^–1), excellent rate capability, and enhanced electrochemical stability, with 91.7% retention after 1000 continuous charge–discharge cycles even at a high current density of 80 mA cm^–2