NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 32
·13755-13763
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IF 3.288
Xia Wang,Wulan Zeng,Wenjing Liu,Xiaoyu Cao,Chunhui Hou,Qi Ding,Yaxuan Lü
The design and development of low-cost sorbents is vital for CO2 capture from flue gases. In this study, the lignite char from Ordos coal (SE) was treated by a one-step KOH activation method to prepare microporous activated carbons for CO2 adsorption. The textural pore properties, surface functional groups and element contents of SE before and after activation were characterized and discussed; the effects of the mass ratio of KOH to SE, activation temperature and time, as well as the adsorption temperature on CO2 adsorption for prepared porous sorbents were investigated and optimized; the isosteric heat of adsorption and adsorption kinetics for the optimized sorbent were further calculated and fitted. When the mass ratio of KOH to SE was 1 : 1, the activation temperature and time were 700 °C and 120 min respectively, and the sorbent of K/SE700(120) showed an adsorption capacity of 1.35 mmol g−1 at 20 °C, which dropped by 2.96% after ten regenerations. The Langmuir adsorption isotherms fitted the adsorption data of K/SE700(120) well, and the isosteric heats of adsorption were 11–13 kJ mol−1, showing the physisorption characteristic. In addition, the good fit of the adsorption data to the Avrami model suggested that there are multiple adsorption routes for K/SE700(120).
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Qihuang Huo,Yahui Wang,Huijun Chen,Yu Feng,Lina Han,Weiren Bao,Liping Chang,Jiancheng Wang,Kechang Xie
It is a win–win strategy to prepare mercury sorbents from low-cost high-sulfur raw materials. In part 1, mercury sorbents with excellent performance were prepared from high inorganic sulfur coal through KOH activation. However, this method does not work for high organic sulfur coal. In this work, a two-step preparation method is developed to prepare mercury sorbents from high organic sulfur coal. The first step is the co-pyrolysis/carbonization of Fe 2 O 3 and coal, during which organic sulfur in coal is converted into FeS x . XPS shows that the percentage of S x 2– /S on the surface of the carbonized samples gradually increases from 5.4% to 22.2% with the m(Fe):m(S o ) ratio from 0:4 to 5:4. The second step is KOH activation, and it converts FeS x into various S species, including C-S, S 0 , S 2 2− and S 2− . Among the prepared mercury sorbents, LF+3Fe/4S-A (m(Fe):m(S o ) = 3:4) shows the best mercury removal performance, and its mercury removal efficiency remains above 84% for 120 min under N 2 +O 2 at 120 °C. The Hg-TPDD and XPS results indicate that S*, including C-S, S 0 and S 2 2− , are the major active sites for mercury removal rather than Fe element, and HgS is the main existing form of mercury on the used sorbents. Besides LF coal, this two-step process is also applicable to other high organic sulfur coals (such as LL coal, WJZ coal, and SY coal) and high-sulfur petroleum coke.
研究领域:
环境科学
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能源材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Biobased Materials and Bioenergy
·
2014
·Vol. 8
·期 1
·35-42
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IF 0.586
Wang Xuyu,Wang Sai,Yin Xueqiong,Chen Junhua,Zhu Li
Activated carbon (AC) was prepared from cassava residue using a two-step activation, including carbonization and subsequent KOH activation. The conditions of activation were optimized through single factor and orthogonal experiments. Heating at 700 °C for 90 min resulted in a charcoal
yield of 20%, the optimal condition for carbonization. Factors affecting surface area (S
BET) were KOH/char ratio > activation temperature > activation time. The porous structure of the AC was characterized using the physical adsorption of N2 at 77 °K.
AC with a S
BET of 460–2655 m2/g and pore volume of 0.41–1.198 cm3/g were prepared. Prepared AC had a high proportion of micropores (range: 83.0–92.0%) compared to mesopores. The average diameters of the micropores and mesopores were
in the range of 0.991–1.093 nm and 19.37–37.97 nm, respectively. The highest adsorption capacities for formaldehyde and iodine were 295 mg/g and 1387 mg/g, respectively. SEM images demonstrated the topographic structure of the AC.
研究领域:
材料科学
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环境工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2025
·
IF 5.4
Chang Liu,Xiaowei An,Peifen Wang,Xuli Ma,Xingfa Li,Xin Chen,Yongguo Li,Xiaogang Hao,Xiaoxu Zhang,Abuliti Abudula,Guoqing Guan
In this study, a highly efficient and cost-effective adsorbent for gaseous iodine, nitrogen-doped KOH-activated coconut shell biochar (NKBC), is presented. A two-step pore expansion assisted by KOH activation process, enhanced by nitrogen doping, created a hierarchical porous structure with ultra-high specific surface area of 2977.90 m 2 /g, large total pore volume of 2.19 cm 3 /g and available micropore volume of 1.17 cm 3 /g, resulting in an iodine adsorption capacity of 6635 mg/g at 75℃ within 3 hours. The low desorption rate (12.93 % at room temperature) highlights the material's stability. Grey relational analysis identified specific surface area and pore structure as key determinants of adsorption capacity, while pore size distribution and nitrogen content significantly influenced desorption. DFT calculations confirmed the enhanced iodine adsorption by nitrogen functionalities and the effectiveness of micro- and narrow mesopores in iodine capture. This sustainable approach offers a significant advancement in developing high-capacity adsorbents for the effective remediation of radioactive iodine.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Tao He,Xiaoben Zhao,Shuainan Wang,Song He,Ye Li
This research delves into the combined impact of employing sodium lignosulfonate as a feedstock, along with its inherent self-activating property and co-activation with KOH, in the preparation of activated carbon. Studies suggest that the natural activator, Na, aids in the internal creation of pores, thereby decreasing the reliance on KOH. The resulting activated carbon boasts a substantial specific surface area of 3362 m²/g, a significant micropore volume of 1.3435 cm³ /g, and considerable doping levels of nitrogen (1.09 %) and sulfur (2.46 %). Analysis of CO 2 adsorption indicates that the adsorption heat escalates with the quantity of CO 2 adsorbed, highlighting the pivotal role of micropores in this process. Monte Carlo simulations further demonstrate that narrowing the pore size range boosts CO 2 adsorption uptake. Nevertheless, as the temperature rises, the ability of micropores to capture carbon dioxide decreases, as shown by the increasing difference in adsorption capacity from 0 °C to 25 °C.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Yi Qin,Bo Chai,Chunlei Wang,Juntao Yan,Guozhi Fan,Guangsen Song
A porous biochar (BC) was prepared using the recycled agricultural waste rape straw as resources by combining high temperature carbonization with KOH activation procedure, and applied into tetracycline hydrochloride (TC) adsorption. The multiple characteristic techniques were adopted to investigate the structures and properties of as-prepared BC. The results demonstrated that the BC activated by KOH would possess the more graphite-like structures, more abundant oxygen-containing functional groups, and larger specific surface area (1531 m 2 /g) comparing with unactivated BC, which were favorable for the TC adsorption. The effects of initial TC concentration, solution pH value, salt ionic strength and adsorption temperature on the adsorption performances were explored in detail. The adsorption data could be well fitted by the pseudo-second-order kinetic model and Freundlich isothermal model. The maximum adsorption capacity of KOH activation BC could reach 325.07 mg/g at 30 °C. The endothermic and spontaneous properties of the adsorption system was implied by thermodynamic study. The adsorption TC mechanism of KOH activation BC was involved in the pore filling, π-π electron donor-acceptor interaction, hydrogen bonding and electrostatic action. Regeneration experiments showed that the TC removal efficiency could still attain 97.0% even after six cycling experiment, suggesting that the BC had the excellent reusability and stability. These results indicate the feasibility of a win-win strategy for the application of agricultural waste to water remediation.
研究领域:
环境科学
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农业资源利用
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Dan Yu,Yushuang Ma,Mingfeng Chen,Xiaoping Dong
Biomass precursors with natural porous structure and multifarious heteroatoms are desirably sustainable precursors for synthesis of carbon materials for energy and environmental applications. Herein, we reported wax gourd based porous carbons (WGPCs) with developed micro/mesoporous structures via potassium hydroxide (KOH) chemical activation . The optimized material that is denoted as WGPC-4 exhibits high specific surface area (2919 m 2 g −1 ) with oxygen and nitrogen contents of 17.9 at.% and 1.0 at.%, respectively. In a three-electrode system, the WGPC-4 electrode presents high specific capacitance of 333 F g −1 at current density of 1 A g −1 . Meanwhile, the assembled symmetrical cell using aqueous electrolyte (0.5 M Na 2 SO 4 ) has high specific capacitance (167 F g −1 at 1 A g −1 ), stable cycling characteristics (93% capacitance retaining after 5000 runs) and excellent energy density of 19.2 Wh kg −1 . Furthermore, these WGPC-4 electrodes were assembled into an all-solid-state supercapacitor using KOH/polyvinyl alcohol (PVA) gel as solid electrolyte , whose specific capacitance is 258 F g −1 at 1 A g −1 , retention at the 2500th run is 87% and energy density is 13.0 Wh kg −1 under a high power density. These materials with excellent structural characteristics are an ideal candidate for high-performance supercapacitors .
研究领域:
材料科学
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能源与环境科学
✓ 已验证
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2022
·
IF 3.806
Yan Zhang,Yun-Peng Zhao,Le-Le Qiu,Jian Xiao,Fa-Peng Wu,Jing-Pei Cao,Yong-Hui Bai,Fang-Jing Liu
High-performance supercapacitors extremely depend on reasonable microstructure of electrode materials, but how to efficiently control the pore structure of principal carbon materials remains a challenge. In this study, corncob-based porous carbon (CPC X ) with controllable pore structures is synthesized by means of KOH activation strategy, and the technical parameters of KOH activation are comprehensively investigated including activation temperature, activation time and KOH/biochar ratio. The optimal sample with a KOH/biochar mass ratio of 3 activated at 650 °C for 1 h (denoted as CPC 650 – 1-3 ) possesses sub-nanopores concentrated at 0.6 nm and 0.8 nm, and larger micropores distribute at 1.2 nm and 1.5 nm. These highly cross-linked microporous structures provide accessible specific surface area (SSA) for electrode materials and act as high-speed channels for fast ion diffusion and transfer. The activated carbon material has a high SSA (2998 m 2 g −1 ) and a large V micro /V meso ratio of 8.26. The specific capacitance of CPC 650 – 1-3 reaches 258 F g −1 at 0.5 A g −1 and remains a satisfied retention of 74 % even at 10 A g −1 . Moreover, CPC 650 – 1-3 //CPC 650 – 1-3 symmetric supercapacitors exhibit a high energy density of 6.4 Wh kg −1 at power density of 500.1 W kg −1 . It also has a capacitance retention of 90.1 % after 10,000 cycles, highlighting its excellent cycle stability. These results indicate that corncob-based microporous carbon materials have broad application prospects in promoting the high added-value utilization of biomass waste and the development of high-performance supercapacitors.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
IF 6.9
Gao Feiyue,Zhou Chuncai,Shi Jiaqian,Huang Yan,Li Wenwen,Liu Guijian,Li Xin
Coal tar residue (CTR) is a hazardous industrial waste and its appropriate disposal evokes great concerns. In this work, superb surface area porous carbon was synthesized from extracted residue in CTR through one-pot KOH chemical activation and applied for phenol adsorption. Results revealed that micro-mesoporous porous carbon (MPC-3–850) with ultrahigh specific surface area of 5465 m 2 /g, and multiple oxygen-containing functional groups was synthesized at optimized conditions (mass proportion of KOH/MCTR was 1:3, pyrolysis temperature was 850℃). Adsorption results showed that the optimized absorbent dosage was 2 g/L, and adsorptive equilibrium time was 120 min. Maximum adsorption capacity of MPC-3–850 in experiment was reached higher than 360 mg/g and decreased at elevated temperatures. Near neutral conditions (pH=6–8) and lower co-existing ions (Mg 2+ , K + , Na + ) strength had a slightly effect on adsorption performance. Adsorption process adhered to pseudo-second-order kinetic and Freundlich isotherm models, and was exothermic and spontaneous. The adsorption mechanism included pore filling, van der Waals forces, electron donor-acceptor interaction, hydrogen-bonding interaction, and π-π interaction. MPC-3–850 had a good ability to adsorb phenol in real coke wastewater and excellent adsorption capacity after 4 desorption-adsorption cycles.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
·
IF 5.316
Shuangyu Wang,Zhiwei Hu,Zhongmou Pan,Dewei Wang
The construction of heteroatom-doped hierarchical carbon frameworks has attracted significant research attention as high-performance electrode materials for supercapacitors. Herein, a facile one-step Mohr’s salt-assisted KOH activation strategy has been developed for the production of S-doped hierarchical carbon frameworks with large specific surface area from sustainable spruce bark. We found Mohr’s salt plays multiple roles during the synthesizing process by simultaneously acting as an S source, the template to generate mesopores, and the co-activator beyond KOH. As the electrode for supercapacitors, the high specific capacitance of 281 and 156 F g −1 can be achieved in aqueous electrolyte and ionic liquid electrolyte at 1 A g −1 , respectively. More importantly, the electrode also displays excellent rate capability where a high capacitance can be maintained at large charge-discharge operation. Moreover, the supercapacitor device also demonstrated an energy density is high up to 66.26 Wh kg −1 at the power density of 875 W kg −1 in ionic liquid electrolyte. These results acquired could offer a versatile way to convert renewable biomass into value-add porous carbon for electrochemical energy-storage applications.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2020
·
IF 0.593
Shuai Ru,Zhaoquan Ai
2,2’-Bipyridine with strong coordination ability for metal ions was used to prepare N-doped porous carbon materials by a facile method of solution agitation and annealing, with KOH as the activated solvent. Applied to supercapacitors, these porous carbon materials exhibit high specific capacitance and outstanding rate performance, which are attributed to their larger specific surface area, richer pore structure, and N-doping after KOH activation, leading to fast electron transport and increased ion storage in the unique architecture.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Jian Tian,Lu Wang,Lixue Qi,Qun Li,Daohua Sun,Qingbiao Li
As an abundant and renewable biological resource, straw has been attracting wide attention due to its distinctive tubular structure and property. Herein, soybean straw was pretreated by KOH and was used as a support for Pt nanoparticles (NPs) to realize efficient benzene combustion. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of straw-derived samples illustrated the channel wall with open macropores and uniform distribution of Pt NPs in the straw skeleton. As a result, the temperature for 90% benzene conversion (T90%) by Pt/KAC-3 (Pt/KAC-n, where n represents the mass ratio of straw to KOH that was varied between 1:1, 1:2, and 1:3) was determined to be 179 °C under a space velocity (SV) of 120 000 mL/(g·h). Additionally, thermal stability was enhanced to nearly 96 h. This performance is predominantly attributed to its inherent channel structure, which has open and accessible pores, resulting in a uniform distribution of Pt NPs. Such structure enables the rapid transfer of benzene molecules between channels and ensures the accessibility of Pt NPs. Furthermore, the diffusion properties were confirmed by Fick’s second law. This study demonstrated a design of more efficient catalysts while using a renewable and abundant biomaterial.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）