期刊：
Separation and Purification Technology,2022年303:122237 ISSN：1383-5866
通讯作者：
Xiancheng Ma<&wdkj&>Qingding Wu<&wdkj&>Liqing Li
作者机构：
[Wu, Yi; Wu, Qingding; Ma, Xiancheng] Cent South Univ Forestry & Technol, Coll Mech & Elect Engn, Changsha 410083, Hunan, Peoples R China.;[Li, Liqing; Zeng, Zheng; Guo, Yang] Cent South Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Su, Rongkui] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Yao, Xiaolong] Beijing Technol & Business Univ, Dept Environm Sci & Engn, 11 Fuchenglu, Beijing 100048, Peoples R China.;[Wang, Shaobin] Univ Adelaide, Sch Chem Engn & Adv Mat, 108 King William St, Adelaide, SA 5005, Australia.
通讯机构：
[Xiancheng Ma; Qingding Wu] C;[Liqing Li] S;College of Mechanical & Electrical Engineering, Central South University of Forestry and Technology, Changsha 410083, Hunan, China<&wdkj&>School of Energy Science and Engineering, Central South University, Changsha 410083, Hunan, China
关键词：
Porous carbon;Pore structure;Nitrogen and oxygen groups;Iodine capture
摘要：
The removal of radioactive iodine species during nuclear accidents and nuclear fuel reprocessing is crucial to nuclear safety, public health and environmental protection. Here, a series of nitrogen-doped porous carbon derived from benzimidazole (NBCs) with well-developed pore structure were prepared. During KOH activation, the potassium salt formed at 600-700 degrees C is mainly K2CO3 and K2O, and the pore size obtained is mainly microporous. With the temperature increases, the K2CO3 and K2O are converted to KOCN, which generates mesopores. NBCs were subsequently tested for gaseous iodine and solution iodine. The results show that NBC800-2 exhibits the highest iodine vapor adsorption capacity (7873 mg/g) at 75 celcius. Theoretical calculations and experimental data show that the iodine adsorption of NBCs for iodine vapor is mainly determined by pore structure, especially micropores and narrow mesoporous. The effect of nitrogen and oxygen doping on the adsorption capacity of gaseous iodine is limited. In the cyclohexane solution, the adsorption capacity of NBCs for iodine is mainly determined by micropores. In KI/H2O solution, the iodine adsorption mainly depends on mi-cropores and narrow mesopores, which is completely different from the result of iodine adsorption in cyclo-hexane. This is mainly due to the fact that I3- has a larger diameter than I2, and the adsorption energy of I3- (82.8 kJ/mol) on the carbon surface is higher than that of I2 (58.1 kJ /mol). Moreover, Langmuir model can better describe the adsorption process of iodine in cyclohexane and KI/H2O solution than Freundlich model, which proves that the process is mainly monolayer formation. This study provides insights for the further design and development of adsorbents for iodine capture from nuclear waste and nuclear accidents.
期刊：
Separation and Purification Technology,2021年269:118690 ISSN：1383-5866
通讯作者：
Zheng Zeng<&wdkj&>Liqing Li
作者机构：
[Wu, Qingding; Ma, Xiancheng] Cent South Univ Forestry & Technol, Coll Mech & Elect Engn, Changsha 410004, Hunan, Peoples R China.;[Chen, Ruofei; Li, Liqing; Zeng, Zheng; Liu, Baogen; Xu, Xiang] Cent South Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Che, Meihong] Hunan Normal Univ, Coll Chem & Chem Engn, Changsha 410012, Hunan, Peoples R China.;[Su, Changqing] Hunan Univ Technol & Business, Inst Big Data & Internet Innovat, Changsha 410205, Hunan, Peoples R China.
通讯机构：
[Zheng Zeng; Liqing Li] S;School of Energy Science and Engineering, Central South University, Changsha 410083, Hunan, China
关键词：
Porous carbon;Ultrahigh surface area;Oxygen groups;VOCs adsorption and separation;GCMC
摘要：
In this study, biomass-based hierarchical porous carbons (HPCs) were synthesized by developing a cost-effective strategy that combines pyrolysis with KOH activation. The highest surface area of HPCs is up to 3936 m(2) g(-1), which presents record-high acetone (26.1 mmol g(-1) at 18 kPa) and methanol (46.9 mmol.g- 1 at 15 kPa) adsorption capacity at 25 degrees C. Based on experiments and molecular simulations, the total pore volume mainly determines adsorption amount of acetone and methanol at relatively high pressure. However, the oxygen groups can provide adsorption sites for acetone and methanol at relatively low pressure, which is attributed to electrostatic interaction between gas molecules and carbon frameworks. Additionally, the narrow micropore determines the acetone/methanol selectivity at relatively low pressure, and the oxygen groups have no benefit effect on acetone/methanol selectivity. Therefore, this work provides theoretical and experimental support for the design, preparation, and application of VOCs adsorbents.
摘要：
The heteroatom-doped porous carbon is an effective strategy to improve the CO2 uptake. However, there are obvious contradictory conclusions in the previous reports regarding the influences of nitrogen groups and pore sizes. Besides this, previous researches about CO2 capture and CO2/N-2 selectivity on nitrogen-doped carbon materials often ignore the effect of oxygen-containing functional groups. Herein, we successfully synthesized rich oxygen and nitrogen doped carbon materials by hydrothermal treatment using tobacco stem and ethylenediamine, respectively. The obtained porous carbons exhibit high surface area (906-2940 m(2) g(-1)). From the experimental results, at 1 bar, NC600 exhibits the superior CO2 adsorption of 4.33 mmol g(-1) and 6.54 mmol g(-1) at 25 degrees C and 0 degrees C, respectively. Based on GCMC simulation, we can roughly estimate that the contribution of pore structure and functional groups is 62% and 38%, respectively. Nitrogen and oxygen-doped porous carbons exerts a greater influence on the CO2/N-2 selectivity because of the electrostatic interactions enhancement between carbon surface and CO2 molecules. The study is expected to better understand the role of functional groups and pore structure on CO2 capture and CO2/N-2 selectivity.
作者机构：
[董俊辉; 吴庆定; 夏余平; 彭博] Institute of Processing Technologies of Materials, Central South University of Forestry & Technology, Changsha, 410004, China
通讯机构：
[Wu, Q.-D.] I;Institute of Processing Technologies of Materials, Central South University of Forestry & Technology, Changsha, China
作者机构：
[Peng, Bo; Zhang, Hong; Wu, Qing Ding; Dong, Jun Hui] Institute of Processing Technologies of Materials, Central South University of Forestry and Technology, Changsha, China
摘要：
For the purpose of preparing stern bearings adapted to water-lubricating environment to replace natural lignumvitae, preparing bearings with solid lubricant of electromechanical equipment applied in some industries such as textile, food and healthcare to replace sintered bronze, and preparing advanced automotive upholstery, appliance and artware to replace natural rosewood and ox bone, three published patents including “a preparation method of artificial lignumvitae” were used to prepare artificial lignumvitae with a better wear resistance than natural lignumvitae. As the materials for sliding bearing, the main performance of artificial lignumvitae meets the requirement for sintered bronze FZ2365. It explores a new way to develop functional biomass materials with wood waste in urban and rural area while ensure its high quality and cleanness.
