One-pot microwave-assisted synthesis of porous reduced graphene oxide as an electrode material for high capacitance supercapacitor

One-Step Synthesis of Fragment-Reduced Graphene Oxide as an Electrode Material for Supercapacitors

“…Moreover, the vibration peak at 1398 cm −1 is assigned to the O−H vibration in carboxyl or water. 37,52 The FT-IR results indicate the incomplete removal of OCFGs on the graphene surface and edges during the hydrothermal As the amount of Al 2 O 3 spacer increases, the (0 0 2) graphite plane's diffraction peak widens and weakens. Based on the evaluation of the Bragg and Scherrer equation, it is observed that the spacer can effectively suppress the aggregation and rearrangement of graphene sheets, thereby promoting fragmentation and obtaining smaller-sized samples.…”

“…In the Bode phase diagram of Figure S10, the phase angle value of FrGO (1:4, 180 °C, 3 h) and rGO (180 °C, 6 h) is ∼87.1°, which approximates the ideal capacitance of 90°. 37,44,63 Real capacitance C′ and imaginary capacitance C″ vs frequency (Hz) curves reflect the relaxation time (t 0 ) and the maximum capacitance at a frequency of 0.1 Hz. 64 According to eq 4, the resulting real capacitance C′ vs frequency is shown in Figure S11.…”

“…where I (A) is the value of constant current in GCD measurement, Δt (s) is the total time of the discharge part, m (g) is the mass of graphene material on the WE, and ΔV (V) is the voltage change during discharge. The specific capacitance C (F/g) value measured by CV in the three-electrode system was obtained according to the following equation 37,39…”

“…More OCFGs could provide large pseudocapacitance, and the macroporous structure could shorten the electron/ion transport path. 37 Some researchers have reported that the particular morphology of electrode materials can enhance specific capacitance. 39−41 Abdillah et al pointed out that the smaller sheet size, due to the shorter ion diffusion path and lower ion diffusion resistance, contributes to easier ion penetration into the active sites.…”

“…According to our previous study, using ZnO as a spacer and hydrochloric acid (HCl) as an etching agent, we can obtain graphene materials with large pore sizes and retain more OCFGs compared with basic etching agents. More OCFGs could provide large pseudocapacitance, and the macroporous structure could shorten the electron/ion transport path . Some researchers have reported that the particular morphology of electrode materials can enhance specific capacitance. − Abdillah et al pointed out that the smaller sheet size, due to the shorter ion diffusion path and lower ion diffusion resistance, contributes to easier ion penetration into the active sites .…”