Nitrogen Doping of Graphite Oxide with 2,3‐Diaminomaleonitrile: A Study of the Structural, Morphological, and Electrochemical Behavior

• Published in: physica status solidi (b) Vol. 259; no. 10
• Main Authors: Chavez-Esquivel, Gerardo, Cervantes-Cuevas, Humberto, de la O Gasca, Martha, Acosta, Dwight
• Format: Journal Article
• Language: English
• Published: 01.10.2022
• Subjects: graphite oxide; imidazole; nitrogen doping; specific pseudocapacitance
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202100634

Graphite oxide (GrO) and 2,3‐diaminomaleonitrile‐doped GrO (GrODAMN) materials are synthesized by the modified Hummers method. Oxidation and N‐doping treatments increase the C/O ratio from 2.49 to 2.88 for GrO and GrODAMN materials, respectively. GrODAMN material shows higher thermal resistance from room temperature to 800 °C compared with GrO material. Furthermore, the hydroxyl, epoxy, and carboxyl vibrational bands observed for GrO are masked after N‐doping and the intensity of the D‐band increases with respect to the intensity of the G‐band. These changes in dipole moment and polarizability of the molecules are associated with defects and disorders in the carbon lattice, which modify the microstructure order caused by the creation of carbon–nitrogen functional groups. GrODAMN material shows 6.14 atomic % nitrogen associated with imine, amide, and/or imidazole functional groups formed during N‐doping. High‐resolution transmission electron microscopy micrographs show polycrystalline regions with irregular polygons, where the interaction between layers of both materials is dominated by van der Waals forces and electrostatic interactions, showing interplanar distances of 3.35 and 7.39 Å. Finally, GrODAMN shows a specific pseudocapacitance value 49% higher than for the GrO material, associated with less reversible processes in redox reactions. The N‐doping of graphite oxide with 2,3‐diaminomaleonitrile increases the interplanar distances and the arrangement of the layers of functional groups O of GrO material with a negative charge, favoring fewer lattice planes with the same orientation. This can prevent the interlaminar carbon atoms from being attacked by the N functional groups, associated with chemical inactivity.