Ultrasound-assisted amine functionalized graphene oxide for enhanced CO2 adsorption
Ultrasound-assisted amine functionalized graphene oxide for enhanced CO2 adsorption
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DOI：
10.1016/j.fuel.2019.03.011
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发表时间：
2019-07-01
期刊：
影响因子：
7.4
通讯作者：
Chatterjee, Riya
中科院分区：
文献类型：
--
作者：
Liu, Yamin;Sajjadi, Baharak;Chatterjee, Riya
本研究讨论了一种新的超声促进胺化技术功能化氧化石墨烯（GO）的CO2吸附。按照改进的Hummer方法合成氧化石墨烯。开发的功能化技术集成了低频超声物理活化与使用四乙烯五胺（TEPA）的化学功能化的优点。声处理剥离的氧化石墨烯的簇，并提高表面积为随后的胺官能化和CO2吸附。在纹理特性，表面功能，热稳定性和元素组成的变化进行了检查之前和之后的氧化石墨烯活化。表征结果揭示了N含量的实质性增加，从原始的0.08%增加到官能化的GO中的4.84%，并且随后官能化的GO中的表面积从289 m2/g减少到198 m2/g，表明TEPA附着到GO结构。CO2吸附实验在分压为0.10 atm的稀CO2下进行。结果表明，超声波-TEPA活化的GO比未活化的GO具有1.2 mmol g（-1）的吸附容量。在303 K时，GO的最大吸附容量仅为0.3 mmol g（-1）。此外，声化学改性吸附剂表现出稳定的循环吸附-再生性能，10次循环后吸附容量仅下降1%。最后，开发的物理化学活化技术的有效性进行了测定，通过比较其吸附能力与文献中发现的吸附剂。
The present study discusses a novel ultrasound promoted amination technique to functionalize graphene oxide (GO) for CO2 adsorption. Graphene oxide was synthesized following the modified Hummer's method. The developed functionalization technique integrates the advantages of low-frequency ultrasonic physical activation with the chemical functionalization using tetraethylenepentamine (TEPA). Acoustic treatment exfoliates the clusters of graphene oxide and enhances the surface area for the subsequent amine functionalization and CO2 adsorption. Changes in textural properties, surface functionalities, thermal stability, and elemental compositions were examined before and after activation of graphene oxide. The characterization results revealed substantial increment of N content, from 0.08 in pristine to 4.84% in functionalized GO and the subsequent reduction in surface area from 289 to 198 m(2)/g in the functionalized GO, indicating attachment of TEPA to GO structure. CO2 adsorption experiments were conducted under diluted CO2 with the partial pressure of 0.10 atm. at 338 K and the results revealed that ultrasonic-TEPA activated GO possessed enhanced adsorption capacity of 1.2 mmol g(-1) over pristine GO. While pristine GO could only achieve the maximum adsorption capacity of 0.3 mmol g(-1) at 303 K. Besides, the sonochemically modified adsorbent showed stable cyclic adsorption-regeneration performance with only 1% reduction in adsorption capacity after 10 cycles. Finally, the effectiveness of the developed physicochemical activation technique was determined by comparing its adsorption capacity with the adsorbents found from literature.