Nanoarchitectured Nitrogen-Doped Graphene/Carbon Nanotube as High Performance Electrodes for Solid State Supercapacitors, Capacitive Deionization, Li-Ion Battery, and Metal-Free Bifunctional Electrocatalysis

Abstract

A three-dimensional nanostructured nitrogen-doped graphene/carbon nanotube composite has been synthesized via a thermal annealing process, using the high surface attachment properties of uric acid (solid nitrogen precursor) with graphene oxide and oxidized multiwalled carbon nanotube. In the synthesis procedures, the attachment of uric acid to graphene oxide surfaces and the oxidized multiwalled carbon nanotubes via hydrogen bonding and electrostatic forces in the solution leads to a lamellar nanostructure during thermal annealing by the proper insertion of carbon nanotubes in graphene layers with nitrogen doping. The resultant composite has good atomic percentage of N (11.2 at. %) and shows superior electrochemical energy storage and conversion properties compared with nitrogen-doped graphene only and physically mixed nitrogen-doped graphene and nitrogen-doped carbon nanotube samples. The composite exhibits high gravimetric and volumetric capacitance (324 F g −1 at a current density of 1 A g −1 ) as electrode in solid-state supercapacitors, superior capacitive deionization (440 F g −1 at a current density of 1 A g −1 ) in 1 M sodium chloride solution, and as high-performance anode in lithium-ion batteries (1150 mAh g −1 at 0.1 A g −1 ) with longterm cycling stability. In addition, the composite demonstrates efficient metal-free bifunctional electrocatalysis toward the oxygen reduction and evolution reactions, comparable with the commercial electrocatalysts.

Enhancement of the supercapacitive properties of laser deposited graphene-based electrodes through carbon nanotube loading and nitrogen doping

“…21 However, taking into account that the mass loading of the obtained films is about 10 mg cm À2 , the corresponding gravimetric capacitances range from about 100-300 F g À1 , being very competitive values. 19,23,26,63 Since the nanostructure and composition of the samples do not significantly differ, we attribute the great change in capacitance to the increase of the film's porosity. A quantitative measurement of the porosity cannot be carried out by the Brunauer-Emmett-Teller (BET) method due to the tiny mass loading of the films.…”

“…[19][20][21][22] Further improvement of the capacitance of the graphene-CNT composites can be obtained through doping with nitrogen-containing chemical groups or by decorating them with pseudocapacitive materials (ternary hybrids). [23][24][25][26] Different approaches are also being investigated for the synthesis of new nanostructured materials with improved performance. 8,27,28 In this respect, laser-based techniques are revealing high potential for the rapid and versatile fabrication of SC electrodes and devices.…”

Recent Advancements of N-Doped Graphene for Rechargeable Batteries: A Review

“…When tested for LIB, the SnO 2 NCs@N-rGO exhibited excellent discharge capacity, cycle life, and rate capability. In another work, N-doped Gp-CNTs lamellar architecture was utilized as anode material for LIB [88]. The N-content was 11.1% that resulted in a high surface area of 293 m 2 g −1 (Table 1).…”

Functional materials in desalination: A review

“…These CDI electrodes revealed distinct electrosorptive capacity (5.01 mg/g) and excellent salt rejection efficiency (~ 93%). Faisal et al [394] developed 3-D lamellar structured nitrogen-doped graphene/CNT via a thermal annealing process. The nitrogen doping into the graphitic network rendered the CDI electrode with a high surface area, enhanced the conductivity, greater pore volume, and an improved interface between the electrolyte and electrodes this in turn helped in accelerated salt adsorption, giving superior capacitive deionization of 440 F. g −1 at a current density of 1 A. g −1 ).…”