An experimental and computational study of graphene oxide functionalized with tris(hydroxymethyl)aminomethane as an electrode material for supercapacitors

Abstract

In this research, graphene oxide (GO) functionalized with tris(hydroxymethyl)aminomethane (T) was synthesized with a simple one-pot method, and applied as an electrode material for supercapacitors. Electrochemical measurements on the synthesized tris(hydroxymethyl)aminomethane-functionalized graphene oxide (GO@T) indicated a specific capacitance of 549.8 F g− 1 at a specific current of 2.5 A g− 1 and a specific capacitance of 358 F g−1 at a specific current of 7 A g− 1 in the potential range of − 0.5–0.5 V versus Ag/AgCl. It also showed a high cyclic stability. According to the results, 80 and 68% of the initial capacitance was retained after 5500 and 9300 cycles, respectively. Density functional theory calculations were used to investigate the quantum capacitance, free energy change during functionalization reaction, and the layer distance of GO and GO@T.

Graphene Acetic Acid‐Based Hybrid Supercapacitor and Liquid‐Gated Transistor

“…[52] Although the R ct value of GAA is similar or higher compared to other devices (Table S2, Supporting Information), this does not affect the gravimetric capacitance of our supercapacitor (fixed current density 1 A g −1 ), indicating a good rate capability of the GAA sample. According to the literature on supercapacitors, the gravimetric capacitance value is only outperformed by GO functionalized by tris(hydroxymethyl)aminomethane, [32] and a few other GRMs such as rGO [35] and FG functionalized by 5-aminoisophthalic acid [53] show similar values. The presence of the hydrophilic group (─COOH) spaced by one methylene unit from the basal plane yields a gravimetric capacitance increase of one order of magnitude with respect to GA, hence GAA shows a slightly better performance compared to pristine rGO (i.e., 400 F g −1 versus 370.8 F g −1 ), whose synthesis requires high power approaches to achieve the proper grade of reduction (see Table S3, Supporting Information, for a more detailed comparison between GAA figure of merits and other GRMs).…”

“…[30,31] These GRMs offered scientists a materials platform for energy storage devices and transistors due to their promising features such as physico-chemical robustness and electrical conductivity. Concerning supercapacitors, there are different high-performing supercapacitors (i.e., gravimetric capacitance > 300 F g −1 ), whose performances rely on GO [32,33] and FG functionalized by hydrophilic/zwitterion groups [34] as well as pristine rGO. [35] The exploitation of hydrophilic/zwitterion groups such as thioamide, [33] arginine, [34] tri(hydroxymethyl)aminomethane, [32] etc.…”

“…Concerning supercapacitors, there are different high-performing supercapacitors (i.e., gravimetric capacitance > 300 F g −1 ), whose performances rely on GO [32,33] and FG functionalized by hydrophilic/zwitterion groups [34] as well as pristine rGO. [35] The exploitation of hydrophilic/zwitterion groups such as thioamide, [33] arginine, [34] tri(hydroxymethyl)aminomethane, [32] etc. favors efficient trafficking of ions inward/outward the bulk of the supercapacitor, whereas the pristine rGO [35] takes advantage of its ill-defined stoichiometry along with the high content of defects, and a satisfactory conductivity.…”

Preparation of a Cu-Doped Graphene Oxide–Glutamine Nanocomposite for Supercapacitor Electrode Applications: An Experimental and Theoretical Study

“…where k B and T are the Boltzmann constants and the temperature (usually 300 K), respectively. 53,68,69 Figure 11a shows the density of the state (DOS) plots obtained for GO and Cu/G-GO. According to the DOS plot of Cu/G-GO, some new electronic states were created, and the values of DOS increased.…”

“…First-Principle Calculations. Density functional theory (DFT) calculations were performed using a Quantum-ESPRESSO code computer program 68 to investigate the geometrical structure and electronic properties of the graphene oxide and the synthesized nanocomposite. For this purpose, the generalized gradient approximation (GGA) in the scheme of the Perdew−Burke− Ernzerhof (PBE) exchange−correlation functional was employed.…”