State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China.
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China.
Chemosphere. 2022 Mar;291(Pt 1):132702. doi: 10.1016/j.chemosphere.2021.132702. Epub 2021 Oct 25.
Nitrogen-doped (N-doped) hierarchical porous carbon was widely utilized as an efficient volatile organic compounds (VOCs) adsorbent. In this work, a series of N-doped hierarchical porous carbons were successfully prepared from the direct pyrolysis process of three food waste components. The porous biochar that derived from bone showed a high specific surface area (1405.06 m/g) and sizable total pore volume (0.97 cm/g). The developed hierarchical porous structure was fabricated by the combined effect of self-activation (Carbon dioxide (CO) and water vapor (HO)) and self-template. The emission characteristics of activation gas analyzed by Thermogravimetric-Fourier transform infrared spectrometer (TG-FTIR) and the transformation of ash composition in the biochar help to illustrate the pore-forming mechanism. Calcium oxide (CaO) and hydroxylapatite were confirmed as the major templates for mesopores, while the decomposition processes of calcium carbonate (CaCO) and hydroxylapatite provided a large amount of activation gas (CO and HO) to form micropores. The materials also obtained abundant N-containing surface functional groups (up to 7.84 atomic%) from pyrolysis of protein and chitin. Finally, the porous biochar showed excellent performance for VOCs adsorption with a promising uptake of 288 mg/g for toluene and a high adsorption rate of 0.189 min. Aplenty of mesopores distributed in the materials effectively improved the mass transfer behaviors, the adsorption rate got a noticeable improvement (from 0.118 min to 0.189 min) benefited from mesopores. Reusable potentials of the hierarchical porous carbons were also satisfying. After four thermal regeneration cycles, the materials still occupied 84.8%-87.4% of the original adsorption capacities.
氮掺杂（N 掺杂）分级多孔碳被广泛用作高效挥发性有机化合物（VOCs）吸附剂。在这项工作中，通过三种食物废物成分的直接热解过程成功制备了一系列 N 掺杂的分级多孔碳。源于骨的多孔生物炭具有高比表面积（1405.06 m/g）和可观的总孔体积（0.97 cm/g）。通过自活化（二氧化碳（CO）和水蒸气（HO））和自模板的协同作用，制备了分层多孔结构。通过热重-傅里叶变换红外光谱仪（TG-FTIR）分析活化气体的发射特性以及生物炭中灰分组成的变化有助于说明成孔机制。氧化钙（CaO）和羟基磷灰石被确认为介孔的主要模板，而碳酸钙（CaCO）和羟基磷灰石的分解过程提供了大量的活化气体（CO 和 HO）来形成微孔。这些材料还从蛋白质和甲壳素的热解中获得了丰富的含 N 表面官能团（高达 7.84 原子%）。最后，多孔生物炭对 VOCs 吸附表现出优异的性能，对甲苯的吸附量高达 288 mg/g，吸附速率高达 0.189 min。大量分布在材料中的中孔有效改善了传质行为，吸附速率从 0.118 min 提高到 0.189 min，这得益于中孔的存在。分层多孔碳的可重复使用潜力也令人满意。经过四次热再生循环后，材料仍占据了原始吸附容量的 84.8%-87.4%。
