Nitrate Ion Adsorption Characteristics of Activated Carbon Fibers with and without Quaternary Nitrogen Effective for Anion Adsorption
| Autor: | Yoshimasa Amano, Yukiyoshi Tsuchiya, Motoi Machida |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Nitrogen
Polymers Surface Properties Inorganic chemistry Acrylic Resins chemistry.chemical_element 010402 general chemistry 01 natural sciences Oxygen law.invention chemistry.chemical_compound Adsorption Nitrate Phenols law Carbon Fiber Formaldehyde Drug Discovery medicine Benzene Nitrates Molecular Structure 010405 organic chemistry Graphene Polyacrylonitrile General Chemistry General Medicine 0104 chemical sciences chemistry Charcoal Oxidation-Reduction Porosity Activated carbon medicine.drug |
| Zdroj: | Chemicalpharmaceutical bulletin. 68(10) |
| ISSN: | 1347-5223 |
| Popis: | By comparing the two types of activated carbon fibers (ACFs), characteristics of adsorption sites for nitrate ion other than quaternary nitrogen (N-Q) were investigated. Using phenol resin as precursors, activation with ZnCl2 was performed, and then heat treatment at 950 °C was carried out to prepare ACFs without N-Q, while ACFs with N-Q was prepared in the same method using polyacrylonitrile-based carbon fiber as precursors. We assessed the amount of functional groups, elemental composition, porous properties, and model of unit crystal size of graphene. For both ACFs with N-Q and without N-Q, equilibrium adsorption amount was not always simply proportional to surface area, but to the average number of benzene rings (Bz-rings) of graphene universally. PhR-5.0Z4 had only 20 benzene rings per graphene unit, but after heat treatment at 950 °C, the number drastically increased to 1088 (PhR-5.0Z4-9.5HT30). However, when the ACFs contained a large amount of oxygen, the number of Bz-rings was limited to 792 (PhR-5.0Z4-Ox-9.5HT30) even after heat treatment at 950 °C, and did not increase sufficiently. Cπ sites are more susceptible to oxygen inhibition than N-Q in adsorbing nitrate ions. For ACFs having Cπ sites as main adsorption sites, the heat treatment at 950 °C without oxidation can enhance the nitrate ion adsorption capacity. |
| Databáze: | OpenAIRE |
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