Journal of Advanced Ceramics
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2015
·Vol. 4
·期 2
·130-134
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IF 0
Gao Yupeng,Wang Libo,Li Zhengyang,Zhang Yafei,Xing Baolin,Zhang Chuanxiang,Zhou Aiguo
Two-dimensional (2D) carbide Ti 3 C 2 was synthesized by exfoliating Ti 3 AlC 2 in HF solution and used for supercapacitive performance investigation in 3 M KOH electrolyte. The specific surface area (SSA) of as-synthesized Ti 3 C 2 was 22.35 m 2 /g. Ti 3 C 2 -based supercapacitor electrodes exhibited good energy storage ability and had a volumetric capacitance 119.8 F/cm 3 at the current density of 2.5 A/g. Moreover, the addition of carbon black into Ti 3 C 2 powders greatly improved the performance of Ti 3 C 2 -based capacitors because carbon black restrained the preferred orientation of 2D Ti 3 C 2 , providing fast ion transport channels, and in turn, decreasing electrical resistance from 16.7 Ω to 3.5 Ω.
研究领域:
材料科学
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电化学
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APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xiangyuan Deng,Yun Liao,Meng Wang,Detao Xiao
Radon (Rn) is an important contributing factor to lung cancer. Activated carbon (AC) is currently the only Rn adsorbent for industrial applications. However, the effect of the key pore size of AC on Rn adsorption remains unclear, and enhancement of the Rn adsorption performance when using AC is still a challenge. In this work, grand canonical Monte Carlo (GCMC) simulations were performed to simulate the Rn adsorption ability of AC with different pore sizes. The adsorption selectivity of AC with pore sizes from 0.42 nm to 0.60 nm for Rn in the atmospheric environment was much greater than that for nitrogen and oxygen. The Rn adsorption performance was also investigated using KOH-modified activated carbon (KAC) with different pore sizes experimentally prepared using high-temperature roasting. The results showed that when the pore volume of KAC was significantly increased to approximately 0.55 nm, the Rn adsorption performance was obviously improved. Its adsorption coefficient reached 6.50 ± 0.11 m 3 kg −1 , which was 46.7 % higher than that of AC. After heating and regeneration in air, the Rn adsorption performance of KAC was basically unchanged. Combined with the comparative analysis using theoretical and experimental results, the relationship between the Rn adsorption performance of KAC and the pore volume at 0.55 nm is determined, and the accuracy of the GCMC calculation results was substantiated. This research provides a theoretical basis and an experimental method for improving the Rn adsorption performance of AC.
研究领域:
环境科学
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材料科学
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高影响因子
WATER AIR AND SOIL POLLUTION
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2026
·Vol. 237
·期 10
·581
·
IF 3.5
Li Zhen,Tang Lian,Tang Min,Zhan Peng,Ouyang Ke,Wu Zhiping
In this paper, a biochar was prepared through hydrothermal carbonization, followed by activation with KOH and pyrolysis, using waste bamboo powder as the feedstock. The efficiency of the KOH-activated bamboo biochar (KBB) as an adsorbent for the antibiotic levofloxacin (LEV) was studied. Results indicated that the maximum specific surface area, mesoporous specific surface area, and total pore volume of KBB sample, designated as HK-80-BC-800–1.5, was obtained under the conditions of 80 g/L KOH, 800 °C pyrolysis temperature, and 1.5 h residence time, holding a LEV adsorption capacity of 178.0 mg/g. Following optimization of the adsorption process, a corresponding Langmuir adsorption maximum of 277.0 mg/g for LEV was simulated under the conditions of 20 mg/L initial LEV, 10 mg adsorbent, and pH 7.0. Besides, the adsorption mechanisms were determined by analyzing the adsorption kinetics and adsorption isotherms and characterizing the samples before and after adsorption. The findings suggest that pore filling, hydrophobic interaction, and hydrogen bonding force are crucial in the adsorption of LEV by KBB. Graphical
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Chemical Science
·
2024
·
IF 7.6
Yonghui Zhang,Xin Xu,Qingxuan Geng,Qingwei Li,Xiuli Li,Yixuan Wang,Zihuan Tang,Biao Gao,Xuming Zhang,Paul K. Chu,Kaifu Huo
Alkali activation was the common method to prepare commercial porous carbon. In a mixed alkali activation system, the role of individual alkali was generally assumed to be the same as in single alkali activation system, and only low corrosiveness of weak alkali was mostly emphasized. However, the intrinsic roles of individual alkali should be finely understanded and redefined to illuminate the activation pathway from the perspective of internal chemical reactions rather than corrosiveness. Herein, combing the in situ TG-MS analysis, DFT calculation and other characterizations, the activation processes were precisely tracked and the activation pathways were proposed. In the mixed alkali activation system, the strong alkali KOH served as the activation promoter, first decomposing into K2O, which then attacks the C-C bonds, forming active reaction sites defined as pore seeds. The weak alkali K2CO3 acted as the activation pathway modifier, CO32− preferentially etched the pore seeds over K2O due to the lower reaction barrier of CO32− interacting with the pore seeds. Consequently, the rough etching reaction of KOH was replaced and suppressed by the gentler action of CO32− forming more micropores. When the ratio of strong to weak alkali was 1:1, the obtained CK1K2-122 owned the highest microporosity (82.61%) and large specific surface area (1962.18 m2 g-1). It exhibited high specific capacitance of 296.7 F g-1 and excellent cycling stability with 98.3% retention after 10,000 cycles. The supercapacitor demonstrated high energy density of 114.4 Wh kg-1 at power density of 17.5 kW kg-1, with a broad potential window of 3.5 V.
研究领域:
材料科学
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化学工程
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PubMed
高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 41
·18012-18018
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IF 4.197
Yongfeng Liu,Yaxiong Yang,Xin Zhang,You Li,Mingxia Gao,Hongge Pan
The thermal dehydrogenation process of the KOH-containing Mg(NH2)2–2LiH system was systematically investigated by identifying changes in the structure and composition of its components by XRD and FTIR. During ball milling, the added KOH reacts with Mg(NH2)2 and LiH to produce MgO, KH and Li2K(NH2)3. During the initial heating process (<120 °C), the newly formed KH and Li2K(NH2)3 react with Mg(NH2)2 and LiH to yield MgNH, LiNH2 and Li3K(NH2)4 along with hydrogen release. Raising the temperature to 185 °C results in a reaction between Mg(NH2)2, MgNH and LiH that gives Li2Mg2N3H3 as the product and further releases hydrogen. As the temperature is increased to 220 °C, Li2Mg2N3H3 reacts with LiNH2 and LiH to produce Li2MgN2H2 and H2. Meanwhile, two parallel reactions between Li2Mg2N3H3, Li3K(NH2)4 and LiH also generate additional hydrogen. Specifically, the KH and Li2K(NH2)3, formed in situ during ball milling, serve as reactants in the dehydrogenation reaction of the Mg(NH2)2–2LiH system, which is responsible for the significantly improved thermodynamics and kinetics of hydrogen storage.
研究领域:
材料科学
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化学工程
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高影响因子
FUEL
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2023
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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
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高影响因子
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
·
2026
·Vol. 1563
·期 1
·e70406
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IF 4.5
Yize Dang,Zilong Chen,Chengzhuang Zhang,Zhiqiang Han,Zinong Zuo,Kun Liang,Jia Fang
The rising concentration of greenhouse gases causes severe global warming, creating an urgent need for efficient and low-cost carbon dioxide (CO 2 ) adsorption technologies. Corn stover is an abundant agricultural waste that is often underutilized, leading to resource waste and environmental pollution. To develop value-added utilization of this material, corn stover−derived activated carbon is prepared via urea predoping and controlled potassium hydroxide (KOH) etching, while the effects of pyrolysis temperature, urea doping ratio, KOH dosage, and activation temperature are investigated. Under pure CO 2 at 25°C, the optimal adsorbent exhibits an equilibrium CO 2 adsorption capacity of 3.57 mmol·g −1 . Under pure CO 2 at 0°C, the equilibrium capacity increases to 5.91 mmol·g −1 , indicating that lower temperature favors CO 2 physical adsorption. Under a typical flue gas composition of 20% CO 2 /80% N 2 at 25°C, the adsorbent achieves a CO 2 uptake of 1.78 mmol·g −1 after 50 min. The adsorbent exhibits an ideal adsorbed solution theory CO 2 /N 2 selectivity of 30.92. The isosteric heat of adsorption ranges from 28.42 to 23.75 kJ·mol −1 . These values suggest predominantly physical adsorption on heterogeneous sites associated with nitrogen functionalities and structural defects. This study offers insights into the design of biomass-derived CO 2 adsorbents based on corn stover. Graphical Corn stover–derived activated carbon is prepared through urea predoping followed by KOH activation. Nitrogen functionalization and pore development provide complementary contributions to CO 2 capture. The optimized sample reaches 3.57 mmol·g −1 at 25°C and 5.91 mmol·g −1 at 0°C under pure CO 2 , and 1.78 mmol·g −1 after 50 min under simulated flue gas, with an ideal adsorbed solution theory CO 2 /N 2 selectivity of 30.92.
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高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
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2026
·
IF 3.3
Zou Yutong,Zhao Jingyuan,Li Haixia
Antibiotic contamination in water bodies has necessitated effective and sustainable wastewater treatment strategies. In this study, durian shell-derived activated carbon (DSAC) was synthesized via pyrolysis combined with KOH activation, and its adsorption performance for antibiotics from aqueous solutions was systematically investigated. DSAC was characterized by FTIR, XPS, Raman, XRD, and BET. The results revealed that DSAC-3 exhibited a high surface area (3008 m 2 g −1 ) and a well-developed porous structure. This study investigated the effects of pH, initial antibiotic concentration, adsorbent dosage, and temperature on the adsorption capacity of DSAC-3 for CHL and TC. The maximum adsorption capacities for TC and CHL calculated by the pseudo-second-order kinetic model reached 581.7 mg g −1 and 425 mg g −1 , corresponding to removal efficiencies of 78% and 45%, respectively. Thermodynamic parameters indicated the spontaneity and exothermic character of the adsorption process. The plausible adsorption mechanism was proposed to be primarily dominated by pore-filling, π-π EDA interactions, and van der Waals forces, with hydrogen bonding and electrostatic interactions as secondary contributors. These findings suggest that DSAC demonstrates great potential as an effective, low-cost adsorbent for antibiotic removal from contaminated water.
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高影响因子
ENVIRONMENTAL RESEARCH
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2022
·
IF 8.431
Shijin Dai,Libing Liu,Hongping He,Bo Yang,Deli Wu,Youcai Zhao,Dongjie Niu
Molten salt has been increasingly acknowledged to be useful in the destruction of chlorine-containing organic wastes (COWs), e.g., organochlorine . However, the operational temperatures are usually high, and local structure and thermodynamic property of the molten salt remain largely unclear. In this study, novel molten NaOH-KOH is developed for organochlorine destruction, and its eutectic point can be lowered to 453 K with 1:1 mol ratio of NaOH to KOH. Further experiment shows that this molten NaOH-KOH is highly-efficient towards the destructions of both trichlorobenzene and dichlorophenol, acquiring the final dechlorination efficiencies as 88.2% and 94.1%, respectively. The organochlorine destruction and chloride salt enrichment are verified by fourier-transform infrared spectrometer . Molten NaOH-KOH not only eliminates the C-Cl and C C bonds, but also traps generated CO 2 , other acidic gases, and possibly particulate matters as a result of the high surface area and high viscosity. This makes it possibly advantageous over incineration for organic waste destruction for carbon neutrality . To sufficiently reveal the inherent mechanism for the temperature dependent performance, molecular dynamics simulation is further adopted. Results show that the radial distance between ions increases with temperature, causing larger molar volume and lower resistance to shear deformation. Moreover, thermal expansion coefficient, specific heat capacity, and ion self-diffusion coefficient of the molten NaOH-KOH are found to increase linearly with temperature. All these microscopic alterations contribute to the organochlorine destruction. This study benefits to develop highly-efficient molten system for COWs treatment via a low-carbon approach.
研究领域:
环境科学
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化学工程
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PubMed
高影响因子
Environmental Science-Nano
·
2022
·Vol. 9
·期 9
·3385-3396
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IF 9.473
Yu Luo,Zonglin Weng,Yuanfang Lin,Bin Han,Xinwen Ou,Yang Zhou,Jin Jiang
Thallium (Tl) is an extremely toxic trace element with high bioaccumulation. Selective and ultrafast Tl+ removal from water is critical to the safety of water resources but remains a grand challenge. Here, by intercalating KOH into multilayered Ti3C2Tx MXene, an efficient adsorbent with coordination/cation exchangeable sites (KOH@Ti3C2Tx) has been developed for Tl+ removal. Almost 99.6% of Tl+ could be removed over optimal KOH@Ti3C2Tx in just 10 s, and the maximal uptake capacity was up to 238.1 mg g−1, which is 3.8-fold larger than that of the pristine Ti3C2Tx (61.4 mg g−1). Moreover, benefitting from a wider working pH window and excellent selectivity, KOH@Ti3C2Tx could quickly remove almost all Tl+ from actual wastewater, demonstrating great potential for water purification. Control experiments and calculations jointly demonstrated that the boosted performance can be attributed to the synergistic effect of the abundant hydroxyl groups and exchangeable K+ sites, in which the hydroxyl groups can capture Tl+via coordination while the K+/Tl+ cation exchange contributes to selectivity and fast uptake kinetics. This work highlights the interaction mechanism of active sites and metal ions, providing fundamental guidance to the selective and rapid removal of heavy metals from water, especially in emergency disposal of heavy metal pollution accidents.
研究领域:
环境科学
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材料科学
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
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IF 4.084
Mi Yan,Hongcai Su,Dwi Hantoko,Ekkachai Kanchanatip,Fauziah Binti Shahul Hamid,Sicheng Zhang,Guobin Wang,Zhang Xu
In this study, the model food waste was gasified to hydrogen-rich syngas in a batch reactor under supercritical water condition. The model food consisted of rice, chicken, cabbage, and cooking oil. The effects of the main operating parameters including temperature (420–500 °C), residence time (20–60 min) and feedstock concentration (2–10 wt%) were investigated. Under the optimal condition at 500 °C, 2 wt% feedstock and 60 min residence time, the highest H 2 yield of 13.34 mol/kg and total gas yield of 28.27 mol/kg were obtained from non-catalytic experiments. In addition, four commercial catalysts namely FeCl 3 , K 2 CO 3 , activated carbon, and KOH were employed to investigate the catalytic effect of additives at the optimal condition. The results showed that the highest hydrogen yield of 20.37 mol/kg with H 2 selectivity of 113.19%, and the total gas yield of 38.36 mol/kg were achieved with 5 wt% KOH addition Moreover, the low heating value of gas products from catalytic experiments with KOH increased by 32.21% compared to the non-catalytic experiment. The catalytic performance of the catalysts can be ranked in descending order as KOH > activated carbon > FeCl 3 > K 2 CO 3 . The supercritical water gasification (SCWG) with KOH addition can be a potential applied technology for food waste treatment with production of hydrogen-rich gases.
研究领域:
能源转化
·
环境工程
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高影响因子
Carbon Capture Science & Technology
·
2025
·
IF 10.5
Tingwei Wang,Xuelong Quan,Zhiqiang Sun,Zhao Sun
Excessive CO 2 emissions lead to a gradual increase in global average temperatures and an increased frequency of extreme weather events. Exploiting advanced materials for CO 2 capture has become a key issue of concern to all countries. In this study, a new biomass carbonization strategy, co-modification by H 2 O 2 and KOH, is proposed to prepare microporous biochar from pine sawdust with high CO 2 adsorption capacity. Results indicate that the co-modification strategy can produce biochar with a specific surface area as high as 3522.7 m 2 /g (with a micropore ratio of 90.3%), which increases by 56.7% compared to the biochar produced by biomass carbonization without H 2 O 2 treatment. The adsorption properties of the co-modification-derived biochar are investigated by CO 2 -TPD and TG, and the biochar exhibits a maximum CO 2 adsorption capacity of 6.60 mmol/g at 30°C and retains over 91.2% of this capacity after 10 cycles. It is revealed that H 2 O 2 -KOH modification can significantly promote the physisorption capacity of the biochar, highlighting the enhanced CO 2 capture efficiency due to alkaline hydrogen peroxide treatment on the biochar and its enhancement in CO 2 capture.
研究领域:
环境科学
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材料科学
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高影响因子
危险品化学品经营许可证（带存储）