Free‐Standing N‐doped Reduced Graphene Oxide Papers Decorated with Iron Oxide Nanoparticles: Stable Supercapacitor Electrodes

Abstract

In this study, graphene oxide paper is obtained via vacuumassisted filtration of graphene oxide solution to prepare selfstanding electrodes for supercapacitors. Simultaneous reduction and N-doping of graphene oxide paper are performed by chemical reduction followed by thermal annealing. Influence of different reduction techniques on the electrochemical properties of the self-standing papers is investigated. N-doped reduced graphene oxide papers are decorated with iron oxide nanoparticles to increase the energy density of the material. Increasing the amount of iron oxide nanoparticles in the composite paper results in enhanced capacitance. In the galvanostatic charge-discharge measurements, iron oxide/Ndoped reduced graphene oxide electrode exhibits specific capacitance of 203 F g À 1 at 0.5 mA cm À 2 . This value is remarkable since the electrode has a high mass loading of 2 mg cm À 2 , which shows that the electrode can be used for practical purposes. Moreover, these electrodes operate in a wide potential window (1.6 V) and exhibit 79 % capacitance retention at 10000 cycles.

Fundamental Insight into the Degradation Mechanism of an rGO-Fe3O4 Supercapacitor and Improving Its Capacity Behavior via Adding an Electrolyte Additive

“…According to the CV results obtained in Figure a, the characteristic peak was caused by the conversion from Fe 3+ to Fe 2+ . Fe 3 O 4 is converted into FeS, which is consistent with the sulfuration of Fe 3 O 4 . − − Due to the mutual attraction of the opposite charges, Fe 2+ in the solution is distributed on the surface of the negatively charged rGO, thus reacting with S 2– and forming the FeS layer . A schematic diagram of growing FeS on the electrode surface is shown in Figure .…”

Pyrolysis Temperature Tunes the Catalytic Properties of CuBTC-Derived Carbon-Embedded Copper Catalysts for Partial Hydrogenation

“…Next, the Raman spectra were measured to investigate the porous carbon structures. Data presented in Figure 3 demonstrate the presence of the expected peaks at 1353 and 1584 cm −1 corresponding to the D-band, associated with the vibrations of electron-deficient sp 3 carbon atoms of defects or with the breathing mode of six-atom rings, and the Gband, 46,47 associated with the vibration of electron-rich sp 2 carbon atoms in a graphitic 2D hexagonal lattice, respectively. Besides, between the two types of carbon species, in the area between 1400 and 1550 cm −1 , there is a valley area "V" contributed by small amorphous carbon.…”

Nanoparticle-enhanced multifunctional nanocarbons—recent advances on electrochemical energy storage applications

“…mixing and layering, but maintaining the ratio of N-doped RGO and Fe 3 O 4 NPs constant. With the same mass loading (2 mg cm −2 ), the composite that was synthesized by the layering method (201 mF cm −2 at 2 mV s −1 in 0.5 M Na 2 SO 4 versus Ag/AgCl) was found to outperform as a supercapacitor electrode compared to the composite prepared by mixing (166 mF cm −2 at 2 mV s −1 ) [63]. In the layering approach, the Fe 3 O 4 NPs were directly exposed to the electrolyte, whereas not all the NPs were available for the surface redox reaction in the case of electrode prepared by the mixing method.…”