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.

通过比较两种类型的活性炭纤维（ACF），研究了除季氮（NQ）以外的硝酸根离子吸附位点的特征。以酚醛树脂为前体，用ZnCl ₂活化进行，然后在950℃下进行热处理以制备不含NQ的ACF，同时使用聚丙烯腈基碳纤维作为前体以相同的方法制备具有NQ的ACF。我们评估了石墨烯的官能团数量，元素组成，多孔性以及单位晶体尺寸模型。对于具有NQ和没有NQ的两种ACF，平衡吸附量并不总是简单地与表面积成正比，而是普遍与石墨烯的苯环（Bz环）的平均数成正比。PhR-5.0Z4每个石墨烯单元只有20个苯环，但在950°C热处理后，该数目急剧增加至1088（PhR-5.0Z4-9.5HT30）。但是，当ACF包含大量的氧气时，即使在950°C的热处理后，Bz环的数量也被限制为792（PhR-5.0Z4-Ox-9.5HT30），并且没有充分增加。在吸收硝酸根离子方面，Cπ位比NQ对氧抑制更敏感。对于具有Cπ位点作为主要吸附位点的ACF，在950℃下进行热处理而不氧化可以增强硝酸根离子的吸附能力。