Peculiar Properties of Mesoporous Synthetic Carbon/Graphene Phase Composites and their Effect on Supercapacitive Performance.
Composites of mesoporous synthetic carbon and the graphene phase were synthesized in aqueous suspension by employing dispersive interactions of both phases. The resulting carbon-based materials were further heat treated in air at 350 °C. The composites and their components were characterized by using adsorption of nitrogen, potentiometric titration, thermal analysis-mass spectrometry, X-ray photoelectron spectroscopy, SEM, high-resolution TEM, and XRD. Then, they were tested as supercapacitors in three-electrode cells and under visible-light irradiation. The composites and the initial carbon share exactly the same pore-size distributions, but they exhibit significant differences in their surface chemistry, wettability, and conductivity. This allowed us to determine the extent of their effects on their capacitive/pseudocapacitive performance. The results showed that features other than the textural properties can increase the capacitive performance by more than 100 %. The synergistic properties of the composites and their sulfur functional group related photoactivity were linked to chemical interactions between the nanoporous carbon phase and graphite oxide during the formation of the composite.
The City College of New York, Department of Chemistry, 160 Convent Avenue, New York, NY 10031 (USA).
Mykola
M
Seredych
Departamento de Química Inorgánica, Universidad de Málaga, Málaga 29071 (Spain).
Enrique
E
Rodríguez-Castellón
The City College of New York, Department of Chemistry, 160 Convent Avenue, New York, NY 10031 (USA). tbandosz@ccny.cuny.edu.
Teresa J
TJ
Bandosz
D025802:Electric Capacitance; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D016062:Porosity
D006108:Graphite
graphene; photoactivity; porosity; supercapacitors; surface chemistry