In this work, graphene-derived N-enriched porous carbons were synthesized by urea modification and KOH activation of thermally shocked graphene oxide. The prepared sorbents were characterized by various techniques and investigated as potential CO₂ capture materials. The as-prepared sorbents possess high CO₂ adsorption capacity of 2.40 mmol/g (25 °C) and 3.24 mmol/g (0 °C) at 1 bar, which is higher than most graphene-based carbons reported previously. The nitrogen incorporation and narrow microporosity are the two major factors that determine CO₂ uptake for these graphene-derived carbonaceous adsorbents under ambient conditions. The adsorption kinetic data of the optimized sample were well-described by the classical Fick’s diffusion model with a high CO₂ diffusion rate. The fast CO₂ adsorption kinetics can be attributed to the short diffusion paths of this sample, which is composed of thin layers of graphene sheets. Moreover, these graphene-derived sorbents also demonstrate excellent stability and recyclability, high selectivity of CO₂ over N₂, suitable heat of adsorption, and excellent dynamic CO₂ capture capacity. As a result, these graphene-derived porous carbons deserve consideration for removal of CO₂ from exhausted flue gas.

中文翻译：

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源自石墨烯的新型氮掺杂多孔碳可有效捕获CO ₂

在这项工作中，通过脲改性和热冲击氧化石墨烯的KOH活化合成了石墨烯衍生的N富集的多孔碳。通过各种技术对制得的吸附剂进行了表征，并将其作为潜在的CO ₂捕集材料进行了研究。所制备的吸附剂在1 bar下具有2.40 mmol / g（25°C）和3.24 mmol / g（0°C）的高CO ₂吸附能力，高于先前报道的大多数石墨烯基碳。氮的掺入和狭窄的微孔率是决定这些石墨烯衍生的碳质吸附剂在环境条件下吸收CO ₂的两个主要因素。最佳吸附样品的吸附动力学数据通过经典的Fick扩散模型和高CO进行了很好的描述₂扩散率。快速的CO ₂吸附动力学可以归因于该样品的短扩散路径，该样品由石墨烯片的薄层组成。此外，这些源自石墨烯的吸附剂还显示出优异的稳定性和可再循环性，CO ₂对N _2的高选择性，合适的吸附热以及出色的动态CO ₂捕获能力。结果，这些石墨烯衍生的多孔碳值得考虑从废气中除去CO ₂。