Synthesis of Reduced Graphene Oxide/Titanium Dioxide Nanotubes (rGO/TNT) Composites as an Electrical Double Layer Capacitor

Abstract

Composites of synthesized reduced graphene oxide (rGO) and titanium dioxide nanotubes (TNTs) were examined and combined at different mass proportions (3:1, 1:1, and 1:3) to develop an electrochemical double layer capacitor (EDLC) nanocomposite. Three different combination methods of synthesis—(1) TNT introduction during GO reduction, (2) rGO introduction during TNT formation, and (3) TNT introduction in rGO sheets using a microwave reactor—were used to produce nanocomposites. Among the three methods, method 3 yielded an EDLC nanomaterial with a highly rectangular cyclic voltammogram and steep electrochemical impedance spectroscopy plot. The specific capacitance for method 3 nanocomposites ranged from 47.26–165.22 F/g while that for methods 1 and 2 nanocomposites only ranged from 14.03–73.62 F/g and 41.93–84.36 F/g, respectively. Furthermore, in all combinations used, the 3:1 graphene/titanium dioxide-based samples consistently yielded the highest specific capacitance. The highest among these nanocomposites is 3:1 rGO/TNT. Characterization of this highly capacitive 3:1 rGO/TNT EDLC composite revealed the dominant presence of partially amorphous rGO as seen in its XRD and SEM with branching crystalline anatase TNTs as seen in its XRD and TEM. Such property showed great potential that is desirable for applications to capacitive deionization and energy storage.

Synthesis, Structural, Morphological, Electrical, and Electrochemical Properties of Ni(OH)2/Reduced Graphene Oxide Composite Materials

“…6, a, all the CVA curves measured for rGO electrodes exhibit almost close to rectangular shapes in the range of 0 V to 0.5 V that is the evidence of a reversible capacitive behaviour of charge accumulation. The transformation of CVA curves with scan rate increasing is typical for EDL charge accumulation type [15]. The pair of well-defined redox peaks is observed on CVA plots of Ni(OH) 2 -based electrode (Fig.…”

Influence of Sputtering Temperature of TiO2 Deposited onto Reduced Graphene Oxide Nanosheet as Efficient Photoanodes in Dye-Sensitized Solar Cells

“…The XRD of rGO had a sharp peak presence at 25.2°, 43.8°, and 45.6° as shown in Figure 9 a. These peaks correspond to (002), (001), and (001) diffraction planes while the 25.2° peak indicated that the reduction process from graphene oxide (GO) was successfully obtained [ 41 , 42 ]. Moreover, less intense peaks at 43.8° and 45.6° indicated highly disordered carbon material [ 32 ].…”

Nitrogen-doped graphene–TiOxNy nanocomposite electrode for highly efficient capacitive deionization

“…59 The mass ratio of N-doped graphene : TiO x N y is approximately 2 : 1, which results in a signicant decrease of specic area and electrochemical active area as opposed to sole N-doped graphene and a further decrease of specic capacitance. 46,60,61 Fig. 5c shows the I-V curves for electrolyte solutions with concentrations of 0.1 mol L À1 , 0.5 mol L À1 , and 1 mol L À1 .…”