Abstract The wastes formed from various industries' activities draw attention to their ability to be used as a natural adsorbent or as a source for activated carbon production. In this study, we aimed to produce activated carbon rich in surface functional groups from biomass. Surface functional groups of activated carbons (AC) were enriched by HNO3 oxidation. The activated carbons were synthesized with H3PO4 using peach stones (PSs), fruit juice industrial wastes, and can be found in abundance in the World and Turkey. The activated carbons' surface properties, such as BET surface area, micro-mesopore volume, and average pore diameter, were determined. The activated carbon with the highest surface area was produced with the impregnation ratio of 3/1 at 400°C (3AC400) as 1399 m2/g. The microporous structures of the 3AC400 synthesized were determined to be more than the mesopore structures. The effects of acid modification on the surface of 3AC400, whose surface characterization was completed, were investigated using HNO3 at different concentrations (15, 30, 45, and 69 % (v/v) HNO3). When the nitric acid concentration used in the modification was increased from 15% to 69%, the BET surface area of pure activated carbon (3AC400) decreased from 1399 m2/g to 15.44 m2/g. Besides, the micropores were wholly clogged, and the mesopore volume decreased from 0.127 cm3/g to 0.042 cm3/g. Vmic/Vtop of 3AC400 was reduced from 0.813 to 0.008. Modification using in this study was found to have a significant effect on the surface area of 3AC400. Nitric acid led micropores to collapse. So the structure of the surface of modified activated carbons has become more mesopores. The surface properties and surface functional group diversity of the synthesized modified activated carbons by various methods were investigated. With 69% nitric acid modification, the amount of carboxyl, lactone, and phenyl groups on the activated carbon surface was increased by 5.3, 9.75, and 9.00, respectively. The nitric acid modification affected the diversity of surface functional groups such as lactone> phenol> carboxyl. As the nitric acid concentration increased, the modified samples' total surface acidity increased, and IEP values shifted from 3.6 to the left. The total acidity value for the 69NAC/90/2 sample has increased approximately seven times that of the total acidity value of 3AC400.

中文翻译：

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改性法富集活性炭表面官能团

摘要 各种工业活动产生的废物引起人们对它们作为天然吸附剂或作为活性炭生产来源的能力的关注。在这项研究中，我们旨在从生物质中生产富含表面官能团的活性炭。活性炭 (AC) 的表面官能团通过 HNO3 氧化富集。活性炭是使用桃核 (PSs)、果汁工业废料与 H3PO4 合成的，在世界和土耳其大量存在。测定了活性炭的表面特性，例如 BET 表面积、微孔体积和平均孔径。在400°C（3AC400）下以3/1的浸渍比为1399 m2 / g生产具有最高表面积的活性炭。合成的 3AC400 的微孔结构被确定为多于中孔结构。使用不同浓度（15、30、45 和 69% (v/v) HNO3）的 HNO3 研究了酸改性对表面表征已完成的 3AC400 表面的影响。当改性中使用的硝酸浓度从15%增加到69%时，纯活性炭（3AC400）的BET表面积从1399 m2/g下降到15.44 m2/g。此外，微孔被完全堵塞，中孔体积从0.127 cm3/g下降到0.042 cm3/g。3AC400 的 Vmic/Vtop 从 0.813 降低到 0.008。发现本研究中使用的改性对 3AC400 的表面积有显着影响。硝酸导致微孔塌陷。所以改性活性炭的表面结构变得更加中孔。研究了通过各种方法合成的改性活性炭的表面性质和表面官能团多样性。69%硝酸改性后，活性炭表面的羧基、内酯和苯基的量分别增加了5.3、9.75和9.00。硝酸改性影响了内酯>苯酚>羧基等表面官能团的多样性。随着硝酸浓度的增加，改性样品的总表面酸度增加，IEP 值从 3.6 向左移动。69NAC/90/2 样品的总酸度值比 3AC400 的总酸度值增加了大约七倍。研究了通过各种方法合成的改性活性炭的表面性质和表面官能团多样性。69%硝酸改性后，活性炭表面的羧基、内酯和苯基的量分别增加了5.3、9.75和9.00。硝酸改性影响了内酯>苯酚>羧基等表面官能团的多样性。随着硝酸浓度的增加，改性样品的总表面酸度增加，IEP 值从 3.6 向左移动。69NAC/90/2 样品的总酸度值比 3AC400 的总酸度值增加了大约七倍。研究了通过各种方法合成的改性活性炭的表面性质和表面官能团多样性。69%硝酸改性后，活性炭表面的羧基、内酯和苯基的量分别增加了5.3、9.75和9.00。硝酸改性影响了内酯>苯酚>羧基等表面官能团的多样性。随着硝酸浓度的增加，改性样品的总表面酸度增加，IEP 值从 3.6 向左移动。69NAC/90/2 样品的总酸度值比 3AC400 的总酸度值增加了大约七倍。69%硝酸改性后，活性炭表面的羧基、内酯和苯基的量分别增加了5.3、9.75和9.00。硝酸改性影响了内酯>苯酚>羧基等表面官能团的多样性。随着硝酸浓度的增加，改性样品的总表面酸度增加，IEP 值从 3.6 向左移动。69NAC/90/2 样品的总酸度值比 3AC400 的总酸度值增加了大约七倍。69%硝酸改性后，活性炭表面的羧基、内酯和苯基的量分别增加了5.3、9.75和9.00。硝酸改性影响了内酯>苯酚>羧基等表面官能团的多样性。随着硝酸浓度的增加，改性样品的总表面酸度增加，IEP 值从 3.6 向左移动。69NAC/90/2 样品的总酸度值比 3AC400 的总酸度值增加了大约七倍。随着硝酸浓度的增加，改性样品的总表面酸度增加，IEP 值从 3.6 向左移动。69NAC/90/2 样品的总酸度值比 3AC400 的总酸度值增加了大约七倍。随着硝酸浓度的增加，改性样品的总表面酸度增加，IEP 值从 3.6 向左移动。69NAC/90/2 样品的总酸度值比 3AC400 的总酸度值增加了大约七倍。