Influence of surface modification with nitric acid on electrochemical performance of agroindustrial waste-based activated carbon
| Autor: | Daniel I. Arango, Juan C. Perez-Osorno, Zulamita Zapata-Benabithe, Erika Arenas |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Scanning electron microscope 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electrochemistry 01 natural sciences Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Dielectric spectroscopy chemistry.chemical_compound Adsorption Chemical engineering chemistry X-ray photoelectron spectroscopy Nitric acid Desorption medicine Electrical and Electronic Engineering 0210 nano-technology Activated carbon medicine.drug |
| Zdroj: | Journal of Materials Science: Materials in Electronics. 29:15557-15569 |
| ISSN: | 1573-482X 0957-4522 |
| Popis: | Two activated carbons (ACs) were superficially modified with nitric acid (HNO3). The ACs were obtained by chemical activation of palm kernel shell, the first one with KOH at a KOH/AC weight ratio of 2/1 and 700 °C (AC–KOH), and the second one with ZnCl2 at a weight ratio of 1/1 and 735 °C (AC–ZnCl2), both at 5 °C min−1. We modified both, the AC–KOH, and the AC–ZnCl2, taking into account the influence of temperature, impregnation time, chemical/precursor weight ratio on the morphology, textural properties, and electrochemical performance. The morphology was characterized by scanning electron microscopy, and the textural properties by N2 adsorption/desorption at 77 K. The superficial chemistry of the samples was characterized using X-ray photoelectron spectroscopy, and the electrochemical performance by electrochemical impedance spectroscopy in 1 M H2SO4. The best electrochemical behavior of approximately 15 μF cm− 2 was obtained with an impedance of 2.9 Ω with HNO3/AC–KOH weight ratio of 1/1 at 25 °C for 4 h. The increase in the interfacial capacitance is attributed to the high superficial nitrogen content (NXPS: 1.8%) that involved faradic processes, as well as to an enhanced hydrophilic character (wettability) and an improved electron transfer caused by the positive charge of nitrogen species in acid electrolytes. |
| Databáze: | OpenAIRE |
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