介孔炭表面性质对吸附去除低浓度氨性能的影响

室内环境中低浓度氨污染普遍存在,影响人的身体健康,而消除这些低浓度的氨相对困难。本文报道了一种适用于低浓度氨吸附去除的介孔炭材料,其性能明显优于经硝酸处理的活性炭材料。该介孔炭采用磷酸铝为硬模板制备,炭表面存在大量含氧官能团,研究显示炭表面羧基和内酯基在吸附氨过程中发挥着重要作用,它们作为酸性中心与氨发生化学作用,可以有效地捕获空气中低浓度的氨污染物。     

Functionalized ordered mesoporous carbon for the adsorption of reactive dyes

A?novel ordered mesoporous carbon containing basic nitrogen functional groups was synthesized by ammonia-tailoring at a temperature of 1173?K and was applied for reactive dye adsorption. The basic nitrogen-containing functional groups incorporated into the carbon surface could enhance the dispersive interactions between the carbon and dye molecules due to the electron-donating effect as well as the electrostatic interactions between the carbon surface and the anions of the dyes. It was found that this novel functionalized ordered mesoporous carbon could increase the adsorption capacity of reactive red 2 at 298?K by around 40?% and 100?% as compared with the unmodified carbon and a commercial activated carbon, respectively. The Freundlich isotherm showed better correlation with the experimental adsorption data of ammonia-tailored samples than the Langmuir isotherm due to the increased surface heterogeneity induced by the nitrogen-containing functional groups. Adsorption of reactive red 2 was an endothermic process as the adsorption capacity increased with increasing temperature. Low desorption efficiency revealed that the adsorption of reactive red 2 on the modified CMK-3 was extremely favorable, tending to be weakly reversible.     

Core‐shell structured magnetic mesoporous carbon nanospheres derived from metal‐polyphenol coordination polymer‐coated Fe3O4 and its application in the enrichment of phthalates from water samples

In this work, core‐shell structured magnetic mesoporous carbon nanospheres were fabricated from the carbonization of metal‐polyphenol coordination polymer‐coated Fe₃O₄ nanoparticles. The preparation method is simple, fast, versatile, and easy to scale up. Magnetic mesoporous carbon nanospheres exhibit a high specific surface area, high superparamagnetism, and high adsorption efficiencies for phthalates. Four phthalates were extracted from aqueous solutions by using magnetic mesoporous carbon nanospheres via magnetic solid phase extraction. Subsequent analysis was performed by using high‐performance liquid chromatography with ultraviolet detection. The analytical method has good linearity in the concentration range of 1–200 ng/mL for diethyl phthalate, diisobutyl phthalate, and dicyclohexyl phthalate, and 3–200 ng/mL for dipropyl phthalate. The limits of detection were in the range of 0.10–0.62 ng/mL. Compared with previous methods, this method has a lower detection limit, wider linearity range, and faster adsorption and desorption rates. The results indicate that magnetic mesoporous carbon nanospheres are suitable for the enrichment of hydrophobic substances from aqueous solutions.     

硬模板法合成磁性石墨化介孔碳及在中药废水吸附处理中的应用

以SBA-15为模板, 蔗糖为碳源, 硝酸铁辅助催化合成磁性石墨化介孔碳复合材料(Fe/GMC). 利用X射线粉末衍射(XRD)、透射电子显微镜(TEM)、N₂吸附-脱附(BET)、拉曼光谱等对反应产物进行了表征. 硝酸铁辅助催化可以在较低碳化温度(900℃)下实现介孔碳的部分石墨化, 并同步生成磁性Fe₃O₄颗粒, 合成的产物比表面积大、孔道有序、磁性强. 运用紫外-可见(UV-Vis)光谱考察了该复合材料对中药红花色素废水的吸附特性,复合材料的吸附速率快、吸附量高, 具有良好的脱色效果并能实现吸附剂的快速固液磁分离.     

有序介孔碳的微波快速合成和表面修饰及其负载性能

以低聚合度酚醛树脂为碳源、三嵌段共聚物F127(Mw=12600,PEO106PPO70PEO106)为模板导向剂,以微波辐照替代传统的烘箱热聚合,在常见功率下(400～800W)快速(15～60min)聚合,并高温碳化获得介孔碳。XRD、TEM、低温N2吸脱附等测试表明所得样品具有高度有序的介孔结构,比表面积和孔容分别可达614m2·g-1和0.47cm3·g-1。合成的介孔碳经NaBH4和胶体钯溶液两步修饰处理,表面被活化并沉积了Pd颗粒,导电性和亲水性均得到改善,载Pt的量和分散性明显提高,Pt/C催化剂的电化学活性面积由4m2·g-1增加到29m2·g-1。     

Adsorption of tetraalkylammonium ions on microporous and mesoporous activated carbons prepared from vinylidene chloride copolymer

The adsorption of tetraalkylammonium ions on microporous (AC-micro) and mesoporous (AC-meso) activated carbons prepared from vinylidene chloride copolymer was investigated. The adsorbed amounts on AC-micro decreased in the order of tetraethyl-, tetrapropyl-, hexadecyltrimetyl-, and tetrahexylammonium bromide. Consequently it is suggested that the pore size of the activated carbon plays an important role in the adsorption. The adsorbed amounts on AC-meso increased with increasing alkyl chain length. In the case of mesoporous activated carbon, hydrophobic interaction between tetraalkylammonium ions and the surface of activated carbons contributes to in the adsorption.     

Mesoporous Carbons of Well-Organized Structure in the Removal of Dyes from Aqueous Solutions

Mesoporous carbons with differentiated properties were synthesized by using the method of impregnation of mesoporous well-organized silicas. The obtained carbonaceous materials and microporous activated carbon were investigated by applying different methods in order to determine their structural, surface and adsorption properties towards selected dyes from aqueous solutions. In order to verify applicability of adsorbents for removing dyes the equilibrium and kinetic experimental data were measured and analyzed by applying various equations and models. The structural and acid-base properties of the investigated carbons were evaluated by Small-Angle X-ray Scattering (SAXS) technique, adsorption/desorption of nitrogen, potentiometric titration, and Transmission Electron Microscopy (TEM). The results of these techniques are complementary, indicating the type of porosity and structural ordering, e.g., the pore sizes determined from the SAXS data are in good agreement with those obtained from nitrogen sorption data. The SAXS and TEM data confirm the regularity of mesoporous carbon structure. The adsorption experiment, especially kinetic measurements, reveals the utility of mesoporous carbons in dye removing, taking into account not only the adsorption uptake but also the adsorption rate.     

碳前驱体在全氟磺酸型碳基固体酸材料设计中的影响

以碳纳米管、介孔碳分子筛和氮掺杂的介孔碳为前驱体,采用全氟磺酸-全氟乙烯共聚物(PTFE)液相沉积方法制备了修饰量相同的三种全氟磺酸功能化碳基固体酸催化剂,利用N₂吸附、热重分析(TG)、透射电子显微镜(TEM)、傅里叶红外变换(FTIR)光谱以及电位滴定等方法对材料的结构和酸性进行了表征.考察催化剂对于苯甲醇与苯甲醚Friedel-Crafts (F-C)反应的催化性能.结果表明,前驱体的比表面积越大,与修饰剂的相互作用越强,越有利于修饰剂在前驱体表面的分散,得到的催化剂表面酸量越多,酸催化活性越好.因此,全氟磺酸功能化的氮掺杂介孔碳在F-C反应中表现出最高的活性和稳定性.     

One‐stage Template‐free KOH Activation for Mesopore‐enriched Carbons and Their Application in CO2 Capture

Activated carbons with a high mesoporous structure were prepared by a one‐stage KOH activation process without the assistance of templates and further used as adsorbents for CO₂ capture. The physical and chemical properties as well as the pore structures of the resulting mesoporous carbons were characterized by N₂ adsorption isotherms, scanning electron microscopy (SEM ), X‐ray diffraction (XRD ), Raman spectroscopy, and Fourier transform infrared (FTIR ) spectroscopy. The activated carbon showed greater specific surface area and mesopore volume as the activation temperature was increased up to 600°C, showing a uniform pore structure, great surface area (up to ~815 m²/g), and high mesopore ratio (~55%). The activated sample exhibited competitive CO₂ adsorption capacities at 1 atm pressure, reaching 2.29 and 3.4 mmol/g at 25 and 0°C, respectively. This study highlights the potential of well‐designed mesoporous carbon as an adsorbent for CO₂ removal and widespread gas adsorption applications.     

功能化有序介孔碳对重金属离子Cu(II)、Cr(VI)的选择性吸附行为

以三嵌段共聚物F127为模板剂, 酚醛树脂为碳源, 正硅酸乙酯为硅源, 三组分共组装合成介孔碳?氧化 硅纳米复合物, 再经HF去除氧化硅, 得到有序介孔碳(OMC). X射线衍射(XRD)、透射电子显微镜(TEM)、低温 N2吸脱附(BET)等测试表明, 所得样品具有高度有序的介孔结构, 比表面积和孔容分别为1330 m²·g^-1和2.13 cm³·g^-1, 平均孔径6.4 nm. 对其先氧化、后氯化、再胺化, 得到不同胺基接枝量的胺化介孔碳(C-NH₂(m), m为加入的乙二胺的质量(g)). 傅里叶变换红外(FT-IR)光谱表征结果证实, 胺基官能团成功接枝到有序介孔碳表面.TEM测试表明介孔碳的有序孔道结构得到了较好的保持. 以有序介孔碳、胺化介孔碳作吸附剂对Cu(II)、Cr(VI)进行选择性吸附研究. 结果表明: 功能化修饰前, 样品对Cu(II)、Cr(VI)饱和吸附量分别为213.33、241.55 mg·g^-1; 修饰后饱和吸附量可分别达到495.05、68.21 mg·g^-1. 功能化介孔碳表现了较强的选择性吸附Cu(II)的能力.     

Ruthenium nanoparticles embedded in mesoporous carbon microfibers: preparation, characterization and catalytic properties in the hydrogenation of D-glucose

Ruthenium (Ru) nanoparticles dispersed in mesoporous carbon microfibers were prepared using alumina microfibers as the templates via a chemical vapour deposition (CVD) route. Characterized data showed that Ru nanoparticles were embedded in the mesoporous carbon matrix. The samples were found to possess a specific surface area as high as 750 m(2) g(-1), pore sizes in the range of 3-5 nm, lengths in the range of 5-10 μm, and a width of about 0.5 μm. The Ru catalysts displayed a remarkably high catalytic activity and an excellent stability in the hydrogenation of D-glucose. The observed good catalyst performance is attributed to the carbon microfiber morphology, unblocked mesoporous structure, and the hydrogen spillover effect induced by the unique surface contact between the Ru nanoparticles and the carbon. In addition, the incorporation of nitrogen significantly improved the catalytic performance due to the enhanced hydrogen adsorption, better wettability, and modified electronic properties of the Ru.     

Kinetics of polydopamine film deposition as a function of pH and dopamine concentration: Insights in the polydopamine deposition mechanism

Highly ordered mesoporous carbon functionalized with carboxylate groups and magnetic nanoparticles has been successfully synthesized. By oxidative treatment using (NH(4))(2)S(2)O(8) and H(2)SO(4) mixed solution, numerous hydrophilic groups were created in the mesopores without destroying the ordered mesostructure of CMK-3. Through the in situ reduction in Fe(3+), magnetic nanoparticles were successfully introduced into the mesopores, resulting in the multifunctional mesoporous carbon Fe-CMK-3. The obtained hybrid carbon material possesses ordered mesostructure, high Brunauer-Emmett-Teller (BET) surface area up to 1013 m(2)/g, large pore volume of about 1.16 cm(3)/g, carboxylic surface, and excellent magnetic property. When used as an adsorbent, Fe-CMK-3 exhibits excellent performances for removing toxic organic compounds from waster-water, with a high adsorption capacity, an extremely rapid adsorption rate, and an easy magnetically separable process. In the case of requiring emergency removal of large amount of organic pollutants in aqueous, the hybrid carbon adsorbent would be an ideal choice.     

Magnetic mesoporous carbon for efficient removal of organic pollutants

Carbon materials such as activated carbons have been used in the field of water and wastewater treatments. However, the lack of mesopore and, particularly, the difficulty in recovering the spent carbon limited their applications. In this work, magnetic mesoporous carbon microspheres were synthesized by impregnating iron oxide precursors in the mesoporous carbon followed by the in situ conversion of the precursors into magnetite nanoparticles. The as-synthesized carbon microspheres with a high surface area of 742?m²/g and large mesopores of ～4.4?nm exhibited an excellent adsorption capacity for aqueous organic pollutants. The superparamagnetic microspheres with a saturation magnetization of 7.15 emu/g can be easily separated from the treated solution by external magnetic field.     

The effect of interfacial microstructure on the lipid oxidation stability of oil-in-water emulsions

Novel rattle-type magnetic mesoporous carbon spheres are successfully prepared using composite spheres with Fe(3)O(4) as core and mesoporous SiO(2) as shell plus solid SiO(2) as a middle layer as templates. These rattle-type spheres possess the magnetization strength of as high as 37.5 emu/g, high and tunable specific surface areas (382-512.6 m(2)/g) due to mesoporous carbon shells. This magnetic rattle-type structure and the readily accessible mesoporous shell are very favoring for the fast adsorption and release of guest objects triggered by external stimulus, for example, the spheres showed very good adsorptive property to dye.     

高功率超级电容器用介孔炭电极材料

以纳米CaCO3为模板、蔗糖为前躯体制备超级电容器用介孔炭电极材料.材料的结构由氮吸附、TEM表征,借助恒流充放电、循环伏安和交流阻抗评价了其在6 mol.L-1KOH电解液中的电化学电容性能.结果表明,蔗糖基介孔炭的比表面积606 m2/g,富含10~30 nm的介孔.恒流放电法测得介孔炭在电流密度50 mA/g下的比电容为125 F/g,大电流倍率性能特别突出.电流密度增大到20 000 mA/g,比电容还保持有88F/g,远高于进口电容炭,该介孔炭是一种很有前景的高功率超级电容器炭电极材料.     

介孔碳-镍复合物对甲基橙的吸附性能研究

以三嵌段共聚物(F127)作为表面活性剂,低分子量酚醛树脂和六水合硝酸镍分别作为碳源和镍源,利用挥发诱导自组装方法制备了有序介孔碳-镍纳米复合物;采用X射线衍射仪和透射电子显微镜分析了复合物的相组成和微结构;测定了样品的氮气吸脱附特性和对甲基橙的吸附性能,采用二级动力学方程和吸附等温线对吸附结果进行了拟合.结果表明,镍纳米微粒的平均粒径约为20nm;当纳米镍的负载量为2%时,复合物样品具有很高的Brunauer-Emmett-Teller(BET)比表面积(1 610m2/g)和较大的孔容(1.29cm3/g).与此同时,复合物样品的氮气吸脱附特性与二级动力学方程拟合结果具有很好的相关性,吸附量高达324mg/g;吸附等温线拟合结果表明,样品对甲基橙的吸附过程为单分子层吸附,与Langmuir吸附等温式的相关性良好.     

Structural and sorption properties of carbon replicas obtained by matrix carbonization of organic precursors in SBA-15 and KIT-6

We have carried out a comparative study of matrix carbonization of some organic precursors (sucrose, polydivinylbenzene, polyphenol-formaldehyde, polyacrylonitrile, acetonitrile) in SBA-15 and KIT-6 silica mesoporous molecular sieves. We have shown that carbon mesoporous molecular sieves of the CMK-8 type, obtained in KIT-6 mesopores, have better adsorption characteristics due to the features of the three-dimensional cubic structure, the larger pore volume and thickness of the walls of the framework. The maximum micropore volume is observed in CMK-3 and CMK-8, obtained by carbonization of polyphenol-formaldehyde and polydivinylbenzene, while the greatest specific surface area is observed on carbonization of sucrose, where the maximum hydrogen adsorption capacity is achieved at a level of ∼1.4 wt.% (77 K, 1 atm). We show that the mesopore surface coverage by hydrogen in carbon mesoporous molecular sieves increases as the degree of graphitization increases.     

Microcalorimetric investigation of high-surface-area mesoporous titania samples for CO2 adsorption

Mesoporous titania powders were synthesized using the triblock copolymer F127 (PEO(106)PPO(70)PEO(106)) as a surfactant template. Two different procedures (ammonia and/or low-temperature treatment at 393 K) were successfully applied to stabilize the mesoporous structure, resulting in significantly increased surface areas and pore volumes with respect to those of the untreated titania powders. Three of these samples were chosen for further investigation by adsorption microcalorimetry. These samples are characterized by high surface areas (varying between 340 and 141 m (2) g (-1)) and a varying degree of crystallization (anatase phase). The samples were compared to nanosized anatase particles treated to 873 K. The adsorption microcalorimetry was carried out using nitrogen and carbon dioxide at 77 and 303 K, respectively, to gain complementary information about the surfaces. Nitrogen at 77 K showed, for the three samples, adsorption enthalpies at low coverage of similar values, approximately -19 to -22 kJ mol (-1), indicating that the probe gas interacts with similar energetic surface sites. Two distinct energetic regions are observed, the first of which increases with increasing pretreatment temperature, which can be related to increased sample crystallinity. The adsorption of carbon dioxide at 303 K showed high adsorption enthalpies (up to approximately 65-80 kJ mol (-1)), highlighting strong interactions of the carbon dioxide with the titania surface at low pressures. Finally, the CO(2) adsorption properties of the titania samples (adsorbed amount and enthalpies of adsorption) are compared with those of other nanosized adsorbents. This comparison shows the potentiality of mesoporous titania powders for the adsorption of CO(2).     

Adsorption of CO2 and H2 on Nitrogen-doped Porous Carbon from Ionic Liquid Precursor

Nitrogen-doped mesoporous carbon material was prepared via a simple one-step thermolysis method via the carbonization of ionic liquid, 1-cyanomethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([MCNIm]⁺[Nf₂T]^-). The nanostructure of the resultant carbon material was characterized by X-ray diffraction(XRD) and transmission electron microscopy(TEM) and the types of N-containing groups of the carbon material were investigated by X-ray photoelectron spectroscopy(XPS). The N-content of the carbon material is 18.6%(mass fraction) based on the elemental analysis. The produced mesoporous carbon material was further used as the solid sorbent for H₂ and CO₂. The hydrogen uptake capacity and H₂ isosteric heat of the carbon material were discussed. Furthermore, the nitrogen-containing carbon material as good sorbent shows relatively high adsorption and separation ability for CO₂ from CH₄, for which the heat of CO₂ adsorption(Q_st) is 31.8 kJ/mol. The mesoporous structure and nitrogen functionality make the carbon material with high adsorption capacity and selectivity for CO₂ and ability to store H₂, indicating that this kind of nitrogen-doped carbon material originated from ionic liquids is a promising sorbent material for high-performance separation and adsorption.     

Magnetic N‐doped mesoporous carbon as an adsorbent for the magnetic solid‐phase extraction of phthalate esters from soft drinks

A new kind of magnetic N‐doped mesoporous carbon was prepared by the one‐step carbonization of a hybrid precursor (glucose, melamine, and iron chloride) in a N₂ atmosphere with a eutectic salt (KCl/ZnCl₂) as the porogen. The obtained magnetic N‐doped mesoporous carbon showed excellent characteristics, such as strong magnetic response, high surface area, large pore volume, and abundant π‐electron system, which endow it with a great potential as a magnetic solid‐phase extraction adsorbent. To evaluate its adsorption performance, the magnetic N‐doped mesoporous carbon was used for the extraction of three phthalate esters from soft drink samples followed by high‐performance liquid chromatographic analysis. Under the optimum conditions, the developed method showed a good linearity (1.0–120.0 ng/mL), low limit of detection (0.1–0.3 ng/mL, S/N = 3), and good recoveries (83.2–119.0%) in soft drink samples. The results indicated that the magnetic N‐doped mesoporous carbon has an excellent adsorption capacity for phthalate esters and the present method is simple, accurate, and highly efficient for the extraction and determination of phthalate esters in complex matrix samples.