高真空低温剥离法制备高储氢性能石墨烯

采用Hummers法液相氧化合成了氧化石墨(GO),通过高真空低温热膨胀法制备得到了高比表面积的石墨烯(GNS)材料。采用X射线衍射(XRD)、傅里叶变换红外(FT-IR)光谱、X射线光电子能谱(XPS)、拉曼光谱(RS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等分析手段对石墨烯样品进行了表征。结果表明,石墨烯还原彻底,呈褶皱的片层状结构,缺陷少;BET测试及氢气高压吸附实验结果表明,通过高真空低温热剥离法制备的石墨烯材料比表面积高达908.3m2/g,并且拥有丰富的孔道结构;在温度为25、40和55℃,压力2500kPa条件下,氢气的吸附量分别达到了1.81%、0.995%和0.44%(质量分数),表明了石墨烯在储氢领域拥有着广阔的应用前景。     

含胺基骨架多孔聚合物的合成及储氢性能研究

以三聚氰胺和对苯二甲醛为原料,通过溶剂热法制备出含胺基骨架多孔聚合物(AFPP),利用傅里叶变换红外光谱仪、扫描电子显微镜、微孔分析仪和储氢分析仪等现代分析手段对其结构和性能进行表征。结果表明:AFPP的主体骨架链接结构为缩醛胺结构(—N—CR1R2—N—);当三聚氰胺和对苯二甲醛摩尔比为2∶3时,合成的AFPP-2比表面积为389.82m2/g,且具有微孔-中孔-大孔的层次结构;储氢性能分析显示AFPP-2在298K、4.72MPa条件下,氢气吸附量达到9.02%(质量分数)。     

格子理论预测氢在碳吸附剂微孔内的过剩吸附

基于Dubinin势论的修正型D-A方程,需用实验数据定义Ps,使其适用性不受到限制,而引入基于格子理论的Ono-Kondo方程,以预测超临界高压氢气在碳狭缝微孔内的过剩吸附.预测了77～298 K温度时,氢在碳吸附剂微孔内的对比过剩吸附量,并与AX-21活性碳的氢吸附实验结果、GCMC分子模拟结果作了比较.结果表明,该方程能反映出超临界流体吸附等温线的特点,并能很好地预测氢气在活性碳微孔内的吸附趋势.     

沥青基活性炭纤维的微孔性及其对NO,SO2和NH3的吸附特性

通过对新开发的沥青基活性炭纤维(ACF)在77K温度下对氮的吸附和303K温度下对苯的吸附研究,考察其微孔性。沥青基ACF具有均匀的微孔,孔径为0.9-1nm,孔体积为0.45-1.0ml/g。也考察了在303K温度下对NO、SO_2和NH_3的吸附行为。不仅对氮和苯而且对NO、SO_2和NH_3的吸附等温线进行了DR关联,作出关联图并讨论了微孔填充。微孔填充度按NO、NH_3、SO_2次序增大。每种气体微孔填充度和等量吸附热随这些被吸附气体的范德华(Van der Waals)力的增加而增加。     

兰炭基均匀超微孔活性炭的制备及其表征

以KNO_3为氧化剂,经5%~15%(质量分数)KOH常温浸渍,在N_2-水蒸气混合气氛下进行控制热分解制备均匀超微孔活性炭。试验选用正交试验法,选择活化温度、活化时间、KOH浸渍浓度、浸渍时间等参数为影响因素,以碘吸附值为考察指标,得到最佳水平组合,活化温度900℃,活化时间1h,KOH浓度15%,浸渍时间24h。对活性炭表征结果如下:最佳样品碘吸附值达840 mg/g。BET比表面积为725cm~2/g,中值孔径为0.489nm,其中微孔容积占总孔容的70.8%,氢气最大吸附量达76.85cm3/g。该样品以超微孔为主,超微孔孔径主要分布在0.45~0.52nm之间,孔分布比较集中,可用于混合气体分离。     

六羧基铜(Ⅱ)配合物的合成和表征及储氢性能

利用溶剂热法合成了一种新型的六羧基铜(Ⅱ)配合物(Cu-MOF)。采用粉末XRD、元素分析、热重分析、红外光谱、SEM和低温N2吸附等测试方法对样品的结构和性能进行了表征,并测试了其77K的储氢性能。结果表明,六羧基铜(Ⅱ)配合物具有丰富的微孔结构,BET和Langmuir比表面分别为2166.3m2·g-1和3484m2·g-1,总孔容积Vp(N2,0.997)为1.24cm3·g-1。77K、4.2MPa时的过量氢气吸附量为4.67%,77K、7.4MPa时总氢气吸附量为7.23%。     

聚苯乙烯基球形活性炭的制备及其对二苯并噻吩的吸附性能

通过水蒸气活化法制备了聚苯乙烯基球形活性炭,并研究了其对二苯并噻吩(DBT)的吸附性能.采用扫描电镜(SEM)、N2吸附、热重分析(TG)以及液相吸附试验考察了球形活性炭的结构特征.结果表明:以苯乙烯离子交换树脂为原料,通过水蒸气活化法,可以得到比表面积979m2/g～1672m2/g的球形活性炭.其中,BET比表面积和孔容随活化时间和水蒸气流量的增加而增大,而孔径小于0.7 nm的窄微孔却减小.球形活性炭对DBT的吸附量可达109.36mg/g,吸附量与比表面积和总孔容关系不大,而与小于0.7nm的窄微孔成正比.球形活性炭在对DBT的吸附过程中存在不可逆吸附.球形活性炭所含窄微孔的孔容越大,脱附所需要的温度越高,不可逆吸附量越大.     

大蒜皮基多孔炭材料的水热法制备及其CO_2吸附性能（英文）

以大蒜皮为碳源,先采用水热法制备炭前驱体,再经KOH活化法制备了高比表面积和高孔体积的多孔炭材料。采用氮气吸附仪、扫描电子显微镜(SEM)和X-射线衍射(XRD)仪对所制多孔炭的孔结构和形貌特性进行表征。结果表明,活化温度对多孔炭材料的比表面积和孔体积影响较大,当活化温度为800℃和KOH/炭前驱体浓度比为2时,得到的多孔炭材料(AC-28)比表面积和孔体积分别高达1 262 m~2/g和0.70 cm~3/g;当活化温度为600℃和KOH/炭前驱体浓度比为2时,多孔炭材料(AC-26)比表面积和孔体积分别为947 m~2/g和0.51 cm~3/g。虽然AC-26样品的比表面积和孔体积均较低,但其微孔率高达98%,使得此材料CO_2吸附性能优异,在25℃和1 bar时的CO_2吸附量高达4.22 mmol/g。常压下影响多孔炭材料中CO_2吸附量的主要因素是微孔率,并不是由比表面积和孔体积决定。当具有合适的孔径结构和比表面积时,生物质基多孔炭材料中微孔率的增加会有效增加CO_2吸附量。     

间苯三酚-甲醛气凝胶的制备及氢吸附性能研究

以间苯三酚和甲醛为前驱体制备出了间苯三酚-甲醛气凝胶(PF)及碳气凝胶(CPF),并对气凝胶的结构进行了表征;采用自动吸附仪测定了1.01×10Pa内和液氮温度下PF/CPF气凝胶的氢吸附性能.实验结果表明在该条件下PF/CPF气凝胶氢吸附等温线为第一类微孔型吸附等温线;氢吸附量质量密度分别为1.73%和2.42%,碳化能显著提高气凝胶的氢吸附性能,有望通过改善气凝胶的结构增加微孔数量来提高氢吸附量以实现实际应用.     

基于偶氮桥连卟啉的共轭微孔聚合物的制备及其表征

以卟啉作为基本构筑单元,通过偶氮键的链接制备得到基于偶氮链接卟啉的共轭微孔聚合物。通过红外(FT-IR)表征,偶氮键(—NN—)的特征吸收峰(1 597cm-1)证明该材料中大量偶氮键的生成。利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对其形貌进行分析,发现该材料表面粗糙且具有很明显的孔结构。热重分析(TGA)表明其在N2中具有很好的热稳定性(195℃失重5%)。利用N2、CO2和H2对该材料进行气体吸脱附实验,结果显示该材料的比表面积达到571m2/g;CO2吸附量可达94.2mg/g(273K);H2吸附量可达8.6mg/g(77K)。CO2和H2的吸附焓(ΔH)经计算分别达到37和7kJ/mol。     

不同结构活性炭对甲苯的吸附性能

考察了不同结构的活性炭样品对高浓度和低浓度甲苯蒸汽的吸附行为,采用低温(77 K)氮气吸附和129Xe-核磁共振方法对所用活性炭的结构进行了表征.并将活性炭对甲苯的吸附性能与其结构进行了关联.结果表明孔容积大的活性炭对高浓度甲苯蒸汽吸附容量大,而具有丰富微孔和较小平均孔径的活性炭对低浓度(2×10-5)甲苯蒸汽具有高的吸附容量.沥青基活性炭纤维对低浓度(2×10-5)甲苯蒸汽表现出较好的吸附能力.随着比表面积的增大,活性炭纤维对低浓度(2×10-5)甲苯蒸汽的吸附容量略有增加.OG5A,OG10A,OG15A和OG20A在30 ℃下对2×10-5甲苯蒸汽的饱和吸附容量分别为202 mg/g,219 mg/g,221 mg/g和235 mg/g.     

Characterization of adsorption removal of hydrogen sulfide by waste biocover soil, an alternative landfill cover

Landfill is an important anthropogenic source of odorous gases. In this work, the adsorption characteristics of H(2)S on waste biocover soil, an alternative landfill cover, were investigated. The results showed that the adsorption capacity of H(2)S increased with the reduction of particle size, the increase of pH value and water content of waste biocover soil. The optimal composition of waste biocover soil, in regard to operation cost and H(2)S removal performance, was original pH value, water content of 40% (w/w) and particle size of ≤4 mm. A net increase was observed in the adsorption capacity of H(2)S with temperatures in the range of 4-35°C. The adsorption capacity of H(2)S on waste biocover soil with optimal composition reached the maximum value of 60±1 mg/kg at oxygen concentration of 10% (v/v). When H(2)S concentration was about 5% (v/v), the adsorption capacity was near saturation, maintaining at 383±40 mg/kg. Among the four experimental soils, the highest adsorption capacity of H(2)S was observed on waste biocover soil, followed by landfill cover soil, mulberry soil, and sand soil, which was only 9.8% of that of waste biocover soil.     

壳聚糖/沸石分子筛复合吸附颗粒的制备与性能

采用实验室自制壳聚糖/沸石分子筛复合吸附颗粒用于处理水中NH₄+-N和NO₃--N,通过优化工艺条件确定最佳壳聚糖/沸石分子筛复合吸附颗粒制备方法,并利用SEM、比表面积（BET）、FTIR和XPS分析壳聚糖/沸石分子筛复合吸附颗粒表面物化特性。结果表明:壳聚糖/沸石分子筛复合吸附颗粒最佳制备条件为:乙酸浓度为4vol%,壳聚糖浓度为7 g/L,振荡时间为10 h,振荡温度为30℃。制得的壳聚糖/沸石分子筛复合吸附颗粒对NH₄+-N和NO₃--N的吸附量分别达到0.636 mg/g和1.952 mg/g,去除率分别为81.60%和40.28%。壳聚糖/沸石分子筛复合吸附颗粒表面形貌呈现较多凸起和微孔,比表面积为391.52 m2/g。FTIR分析结果表明,壳聚糖特征官能团-NH₂和-CH₃已负载于沸石分子筛的基本骨架中。XPS分析结果表明,元素O1s在壳聚糖与沸石分子筛的连接过程中起主要作用,该研究成果可为北方严寒地区净水厂的提标改造提供理论依据。      

Phosphate removal from wastewater using red mud

Red mud, a waste residue of alumina refinery, has been used to develop effective adsorbents to remove phosphate from aqueous solution. Acid and acid-thermal treatments were employed to treat the raw red mud. The effects of different treatment methods, pH of solution and operating temperature on adsorption have been examined in batch experiments. It was found that all activated red mud samples show higher surface area and total pore volume as well as higher adsorption capacity for phosphate removal. The red mud with HCl treatment shows the highest adsorption capacity among all the red mud samples, giving adsorption capacity of 0.58 mg P/g at pH 5.5 and 40 degrees C. The adsorption capacity of the red mud adsorbents decreases with increase of pH. At pH 2, the red mud with HCl treatment exhibits adsorption of 0.8 mg P/g while the adsorption can be lowered to 0.05 mg P/g at pH 10. However, the adsorption is improved at higher temperature by increasing 25% from 30 to 40 degrees C. The kinetic studies of phosphate adsorption onto red mud indicate that the adsorption mainly follows the parallel first-order kinetics due to the presence of two acidic phosphorus species, H(2)PO(4)(-) and HPO(4)(2-). An analysis of the adsorption data indicates that the Freundlich isotherm provides a better fitting than the Langmuir model.     

Single-walled carbon nanotube network with bimodal pore structures of uniform microporosity and mesoporosity

We characterized single-walled carbon nanotubes before and after HNO3/H2SO4 treatments for different times by scanning electron microscopy, Raman spectroscopy, and N2 adsorption at 77 K. Single-walled carbon nanotube assembly revealed a bimodal pore structure of microporosity (surface area of 476 m2 g(-1)) and mesoporosity (surface area of 476 m2 g(-1)) with a high total surface area of 1048 m2g(-1). The microporosity increased prominently after HNO3/H2SO4 treatments, whereas the mesoporosity decreased progressively with the treatment time. The HNO3/H2SO4 treatment of nanotubes induced an aggregation and alignment that should transform larger mesopores of nanotube assemblies into smaller ones, and smaller mesopores into micropores, resulting in the decrease of external surface area. This effect was attributed to the presence of abundant defects on the tube wall that were saturated by functional groups during the acid treatment of the single-walled carbon nanotubes.     

氢氧化钾／石油焦质量配比对活性炭性能的影响

本文以石油焦为原料，采用氢氧化钾化学活化法系统考察了氢氧化钾／焦炭的质量配比（碱／炭，Ｗｂ／Ｗｃ）对活性炭吸附性能和孔隙性能的影响。结果表明，随着碱／炭比的增加，吸附性能显著提高；比表面积，总孔容积，微孔容积和非微孔容积都增加；孔径分布变窄，平均孔径减少。碱／炭比大于等于３∶１时，所得活性炭试样的比表面积大于３０００ｍ２／ｇ。     

一种新型膦酸锆孔材料的合成及其对金属离子的吸附性质

骨架含强配位基的有机无机杂化多级孔材料合成是目前吸附研究的一个重要领域。以bis (hexamethylene) triamino-N, N-bisacetyl-phosphonic acid和ZrOCl₂·8H₂O为原料、应用水热合成技术合成了一种新型膦酸锆多级孔材料ZrPTA, 并通过FT-IR、TGA、XRD、XPS、SEM以及元素分析等手段对制备产物进行了表征。研究结果表明, ZrPTA具有棒状微形貌, 其内部存在大量直径为1.38 nm和1.93 nm的微孔以及直径为2.99 nm的介孔, 其表面积为112.2 m²/g。ZrPTA对水溶液中Pb²⁺、Cu²⁺和Cd²⁺三种金属离子具有良好的吸附作用, 最大吸附量分别为742.7、689.8和627.0 mg/g, 远远高于文献报道值。这一性质使ZrPTA具有潜在的废水处理功效, 显示出诱人的应用前景。     

硫脲改性Fe_3O_4/壳聚糖微球对Hg~(2+)的吸附性能

利用反相悬浮分散法制备Fe3O4/壳聚糖磁性微球,并经硫脲改性(TMCS)用于吸附水溶液中Hg2+。考察了pH值、温度的影响,以及吸附动力学和吸附等温线。结果表明,TMCS为球形,粒径80μm～250μm。TMCS对Hg2+的吸附量随pH值升高而增加,但随温度升高而下降;焓变(ΔH0=-12.93kJ/mol)为负,表明吸附放热;Gibbs自由能(ΔG0=-16.41kJ/mol～-17.22kJ/mol)为负,表明吸附能自发进行。等温吸附线可用Langmuir模型拟合,最大吸附容量2.69mmol/g;吸附动力学可用拟二级模型拟合,表明化学吸附为控速步骤。吸附Hg2+后的TMCS可用0.01mol/L的EDTA脱附,脱附率达91%。     

High performance activated carbon for benzene/toluene adsorption from industrial wastewater

A coal-tar-derived mesophase was chemically activated to produce a high surface area (∼3200 m²/g) carbon with a porosity made up of both micropores and mesopores. Its adsorption capacities were found to be among the highest ever reported in literature, reaching values of 860 mg/g and 1200 mg/g for the adsorption of benzene and toluene, respectively, and 1200 mg/g for the combined adsorption of benzene and toluene from an industrial wastewater. Such high values imply that the entire pore system, including the mesopore fraction, is involved in the adsorption process. The almost complete pore filling is thought to be due to the high relative concentrations of the tested solutions, resulting from the low saturation concentration values for benzene and toluene, which were obtained by fitting the adsorption data to the BET equation in liquid phase. The kinetics of adsorption in the batch experiments which were conducted in a syringe-like adsorption chamber was observed to proceed in accordance with the pseudo-second order kinetic model. The combined presence of micropores and mesopores in the material is thought to be the key to the high kinetic performance, which was outstanding in a comparison with other porous materials reported in the literature.