醇胺改性氧化石墨烯/PVDF共混膜接触器脱硫性能的研究

通过醇胺改性氧化石墨烯(GO)和聚偏氟乙烯(PVDF)共混制备具有SO_2吸附功能的共混膜,用于膜接触器脱硫.考察了GO和乙醇胺(MEA)、二乙醇胺(DEA)、三乙醇胺(TEA)改性氧化石墨烯/PVDF共混膜的SO_2静态吸附性能,并将其用于膜接触器,以NaOH溶液为吸收液研究其脱硫性能,考察了吸附对SO_2在膜中的扩散传递的促进及其对脱硫性能的影响.结果表明,在共混醇胺改性后GO后,膜对SO_2的吸附性能明显提高,其中GO-DEA/PVDF膜表现出了最佳的SO_2吸附性能,平衡吸附量可达7.68mg/g.将GO-DEA/PVDF膜用于膜接触器脱硫时,其对SO_2的吸附作用明显,促进了气体的传质,使该膜显示出较高的脱硫效率以及较好的稳定性.在吸收液流速为30L/h时,GO-DEA/PVDF膜的脱硫率可达69%.     

复合改性活性炭的表征及其吸附模拟烟气中SO_2的研究

为了研究单一金属盐和复合金属盐改性活性炭材料对SO_2吸附性能的影响,以活性炭(activated carbon,AC)为载体,通过水热法制备ZnO/AC复合材料、Fe_2O_3/AC复合材料、ZnFe_2O_4/AC复合材料以及空白AC材料。采用场发射扫描电镜(SEM)、X射线能谱仪(EDS)、X射线衍射仪(XRD)、傅立叶变换红外光谱仪(FTIR)、物理吸附仪(BET)及X射线光电子能谱分析仪(XPS)对复合材料结构及化学组分进行表征,并且在常温条件下考察活性炭复合改性前后对模拟烟气中SO_2的吸附性能。结果表明,复合改性后活性炭材料成功负载金属氧化物活性组分,比表面积孔容减小,孔径增大并且对SO_2的去除效率显著提高。通过AC、ZnFe_2O_4以及4种复合材料脱硫效率的比较发现,负载ZnFe_2O_4的活性炭材料的脱硫效率最高,其比表面积和孔容分别为435.9m~2/g、0.37cm~3/g,脱硫性能试验中样品的击穿时间为136.0min,硫容达到168.3mg/g。     

氧化石墨烯基复合材料对Cr(Ⅵ)的吸附研究

以氧化石墨烯(GO)、氧化铈(CeO2)和改性壳聚糖(DCS)为原料,采用溶液共混法合成氧化石墨烯基复合材料(DCG)。研究了DCG对Cr(Ⅵ)的静态吸附性能,考察了DCG用量、Cr(Ⅵ)质量浓度、吸附时间和吸附温度对吸附效果的影响。实验结果表明,DCG质量浓度为2g/L、废水中Cr(Ⅵ)质量浓度为20mg/L、吸附温度为25℃、吸附时间为90min时吸附效果最好。傅里叶变换红外光谱、扫描电子显微镜和X射线衍射分析表明,DCG为较厚的片层结构,片层表面附着大量点状物,羟基、羧基和氨基为主要活性吸附位点。复合材料DCG明显改变了GO、CeO2和DCS三者的团聚性和亲水性,充分发挥了各自的吸附性能。     

氧化石墨烯/改性磁性壳聚糖复合材料对Cu2+的吸附研究

以石墨粉和壳聚糖为原料,采用Hummers法制备氧化石墨烯,再用四氧化三铁、二乙烯三胺和柠檬酸改性壳聚糖,合成了羧甲基氨基化改性磁性壳聚糖;通过超声分散制备氧化石墨烯水溶胶,再与改性磁性壳聚糖进行复合,成功制得氧化石墨烯/改性磁性壳聚糖复合吸附材料。研究结果表明,在pH=6,吸附剂用量为50mg,吸附时间为90min条件下,氧化石墨烯/改性磁性壳聚糖复合吸附材料对100mL、50mg/L铜离子(Cu~(2+))的吸附容量达到70.3mg/g,且吸附行为符合Freundlich等温吸附模型。     

聚吡咯/石墨烯复合材料的制备和电化学电容性能研究

在70℃的酸性水溶液中,以氧化石墨烯为氧化剂,实现了吡咯的原位氧化聚合。采用傅里叶红外光谱(FTIR),X射线衍射(XRD),X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对复合材料的结构、形貌进行了表征;用循环伏安和恒流充放电对复合材料的电化学性能进行了研究。结果显示:吡咯吸附在氧化石墨烯的表面,发生了原位聚合反应;石墨烯剥离为片层,增大了复合材料的比表面积,聚吡咯/石墨烯复合材料显示了可观的电化学性能,在电流密度为0.5A/g时,电容量达到了695.5F/g,明显高于纯聚吡咯的比电容,循环稳定性也得到了提高。     

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。     

Ce(SO_4)_2改性褐煤半焦对废水中Cd(Ⅱ)的吸附效果

为了提高褐煤半焦对重金属离子的吸附性能,将褐煤用3.0 mol/L H_3PO_4进行活化,将改性剂Ce(SO_4)_2·4H_2O与活化褐煤混合,通过炭化制备出改性褐煤半焦,对改性褐煤半焦的制备条件进行了优化,并通过扫描电镜(SEM)和能谱仪(EDS)对改性褐煤半焦进行了表征。在25℃和静态条件下,研究了改性褐煤半焦对模拟废水中Cd(Ⅱ)的吸附效果,探讨了改性褐煤半焦对废水中Cd(Ⅱ)的吸附条件。结果表明:改性褐煤半焦对模拟废水中Cd(Ⅱ)具有很好的吸附性能,Cd(Ⅱ)的去除率达99.8%。改性褐煤半焦对模拟废水中Cd(Ⅱ)吸附的适宜条件为吸附温度为25℃,Ce(SO_4)_2·4H_2O用量为褐煤质量的5.0%,废水pH值为3.0,Cd(Ⅱ)的起始浓度为40.00 mg/L,吸附时间为2.0 h,Cd(Ⅱ)与改性褐煤半焦的质量比为1∶50。按照改性褐煤半焦对模拟废水中Cd(Ⅱ)吸附的适宜条件,含Cd(Ⅱ)12.90 mg/L的电镀废水经改性褐煤半焦处理后,Cd(Ⅱ)去除率为99.3%,Cd(Ⅱ)的浓度降为0.09 mg/L,可达标排放。改性褐煤半焦可再生利用。     

聚醚P123和四乙烯五胺双功能化Fe-Zr的CO2吸附性能

利用聚醚P123对双金属材料Fe-Zr进行改性合成介孔材料Fe-Zr(P),再利用四乙烯五胺(TETA)对Fe-Zr(P)进行功能化制得TEPA(n)/Fe-Zr(P).采用X射线衍射、X射线光电子能谱、红外光谱、N2吸附-脱附、热重分析等技术对材料结构和热稳定性进行表征,并对CO2吸附性能进行测试.结果表明:P123存在于载体孔道内部;利用TETA对Fe-Zr(P)进行功能化,通过N与Zr配位,从而固载于Fe-Zr(P)表面;温度低于182℃时,TEPA(n)/Fe-Zr(P)保持稳定;TEPA(n)/Fe-Zr(P)中羟基和氨基同时与CO2反应,产生化学吸附,从而提高化学吸附量和N利用率;TEPA质量分数为30％,温度为75℃,气体流速为10 mL/min时,TEPA(30)/Fe-Zr(P)的吸附量可达211.3 mg/g,N利用率为62.7％.循环20次,CO2吸附量保持稳定.     

改性竹炭对水溶液中Cu(Ⅱ)、Cd(Ⅱ)的吸附性能

采用不同方法对竹炭进行改性,寻求吸附效果最好的改性产品,并研究其对溶液中Cu2+、Cd2+的吸附性能,考察了吸附时间、溶液pH值、吸附温度和溶液初始浓度对吸附效果的影响,同时与未改性竹炭的吸附性能进行了对比。实验结果表明:相同条件下,氧化改性竹炭对Cu2+、Cd2+的吸附效果明显优于其他方法改性竹炭和未经改性的竹炭。吸附温度为15℃、25℃、45℃时,氧化竹炭对Cu2+的最大吸附量分别为6.653mg/g、6.702mg/g和7.897mg/g,而氧化竹炭对Cd2+的最大吸附量分别为1.700mg/g、1.826mg/g和2.282mg/g。氧化改性竹炭对Cu2+、Cd2+的吸附均符合Freundlich方程和Langmuir方程。实验证明,氧化竹炭是一种应用前景广泛的重金属离子吸附剂。     

自支撑氮掺杂石墨烯纸柔性电极的制备及其储锂性能的研究

以氧化石墨烯(GO)为原料,尿素为氮掺杂剂,采用固/气界面水热反应的方式,即在反应釜内将GO抽滤得到的氧化石墨烯纸(GOP)与尿素分解产生的氨蒸气相互作用,成功制备出自支撑氮掺杂石墨烯纸(NGP)。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、拉曼光谱(RS)、X射线光电子能谱(XPS)和电化学测试对样品进行形貌结构及电化学性能的表征。测试结果表明:水热条件下尿素能有效地实现氧化石墨烯纸的氮掺杂,氮掺杂量为7.89%;氮掺杂石墨烯纸在100mA/g和500mA/g的电流密度下,充放电循环100周之后,放电比容量可分别保持在288mAh/g和190mAh/g。采用改进的固/气界面水热反应法制备的氮掺杂石墨烯纸较未掺杂石墨烯纸可逆比容量提高了近2.5倍,具有良好的循环稳定性,可为制备高性能的柔性锂离子电池负极材料提供新方法。     

水热合成的MoS2/石墨烯/N-TiO2复合材料的可见光催化性能

以氧化石墨烯(GO)、钼酸、硫脲和TiN为原料,成功制备了MoS_2/石墨烯/N-TiO_2(MGNT)复合材料。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HR-TEM)、X射线光电子能谱(XPS)及紫外-可见漫反射光谱(UV-Vis DRS)等手段测试分析了样品的物相组成、形貌、成分和光吸收性能。紫外-可见漫反射测试结果表明,MoS_2、石墨烯共同修饰及氮掺杂使得TiO_2的吸收带边发生红移,且其可见光吸收性能明显提高。可见光照射下降解亚甲基蓝溶液的实验结果表明,MoS_2/石墨烯共同修饰的氮掺杂TiO_2的光催化降解性能分别是氮掺杂TiO_2(NT)和石墨烯修饰氮掺杂TiO_2(GNT)的1.82倍和1.59倍,其吸附性分别为氮掺杂TiO_2、石墨烯修饰氮掺杂TiO_2的11.14倍和4.77倍。     

Fabrication of chitin/graphene oxide composite sponges with higher bilirubin adsorption capacity

Chitin/graphene oxide (Ch/GO) composite sponges had been synthesized in 11?wt% NaOH/4?wt% urea aqueous solution by a simple method. The structure, thermal stability and mechanical properties of the composite sponges were investigated by scanning electron microscopy, Fourier-transform infrared spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis, and compressive strength measurements. The results revealed that chitin and GO were mixed homogeneously. Interestingly, the composite sponges showed meso-macroporous structure, which played an important role in improving their adsorption properties. Besides, thermal stability and mechanical properties were significantly improved compared with pure chitin sponges. Taking advantages of these fantastic characteristics, the maximum adsorption capacity of composite sponges for bilirubin was up to 422.9?mg/g under the optimized condition, which was not only significantly higher than the adsorption capacities of pure chitin sponges, but also superior to those of many reported adsorbents for removal of bilirubin. Furthermore, blood compatibility evaluations confirmed that this blended sponges had negligible hemolysis and coagulation. Therefore, this work provided a potential possibility to offer Ch/GO composite sponges for removal of bilirubin.     

Graphene oxide (GO) doped CeO2 as potential enhancer of methyl orange degradation

In this article, a simple method for the synthesis of Graphene Oxide-Cerium oxide (GO/CeO₂) is carried out. The prepared sample was characterized in detail, such as scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman, Brunauer-Emmett-Teller technology N₂ adsorption-desorption analysis (BET), photoluminescence (PL) and UV-visible diffuse reflectance spectroscopy (DRS). It was indicated that GO was successfully incorporated into CeO₂. The photocatalytic mechanism of GO/CeO₂ was also explained. The MO solution catalyzed by CeO₂ and GO/CeO₂ was analyzed by a UV-visible spectrometer. The efficiency of GO/CeO₂ degrading methyl orange (MO) is improved from 50% to 87% compared to pure CeO₂ under the visible light. GO/CeO₂ exhibited better photocatalytic performance than CeO₂, which indicated GO doping improved the photocatalytic capacity of the CeO₂ catalyst. It may have potential applications in addressing environmental wastewater.     

Removal of copper ions by modified Unye clay, Turkey

This paper presents the adsorption of Cu(II) from aqueous solution on modified Unye bentonite. Adsorption of Cu(II) by manganase oxide modified bentonite (MMB) sample was investigated as a function of the initial Cu(II) concentration, solution pH, ionic strength, temperature and inorganic ligands (Cl(-), SO(4)(2-), HPO(4)(2-)). Changes in the surfaces and structure were characterized using X-ray diffraction (XRD), infrared (IR) spectroscopy, N(2) gas adsorption and potentiometric titration data. The adsorption properties of raw bentonite (RB) were further improved by modification with manganese oxide. Langmuir monolayer adsorption capacity of the MMB (105.38 mg/g) was found greater than that of the raw bentonite (42.41 mg/g). The spontaneity of the adsorption process is established by decrease in DeltaG which varied from -4.68 to -5.10 kJ mol(-1) in temperature range 303-313 K. The high performance exhibited by MMB was attributed to increased surface area and higher negative surface charge after modification.     

Graphene oxide (GO)-doping SnO2 flower-like structure to enhance photocatalytic activity

The GO/SnO₂ micronanostructure was synthesized by a simple and effective hydrothermal method. The combined characterization methods such as Scanning Electron Microscope (SEM), Transmission electron microscope (TEM), X-ray diffraction (XRD), Element mapping, Energy Dispersive X-Ray Spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), the Raman spectroscopy, the Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), photoluminescence (PL) the Ultraviolet–visible spectroscopy (UV-Vis) and Diffuse reflectance spectrum (DRS) indicated the successful formation of GO/SnO₂ micronanostructure. Moreover, the photocatalytic activity tested with RhB aqueous solution revealed that GO/SnO₂ had excellent photocatalytic properties compared with SnO₂. The photocatalytic efficiency of GO/SnO₂ was much higher (about 2.5 times) than that of pure SnO₂ under visible light irradiation. Based on these test results, we believe that the present work will provide some thoughts for further fabrication of other novel nanostructures and exploration of their applications.     

具有核壳结构的氧化石墨烯/聚醚砜微球的制备及其毒素吸附性能

氧化石墨烯(GO)是一种很具应用潜力的石墨烯纳米材料,由于具备超大的比表面积和表面带电的特性,在对水污染物吸附方面具有优异的性能。然而,氧化石墨烯良好的水中分散性以及纳米尺寸特性,使其在应用过程中难以控制和回收。文中针对此问题,采用聚醚砜对氧化石墨烯进行包覆,通过液-液相分离方法制备出具有核壳结构的氧化石墨烯-聚醚砜复合微球。选用阳离子染料亚甲基蓝(MB)作为被吸附物来考察微球的吸附量、吸附动力学以及吸附热力学。研究发现,该复合微球对MB的最大吸附量高达363.21mg/g,并且可通过提高壳层的亲水性来增大微球的吸附速率。     

Simple facile route for the preparation of graphite oxide and graphene

A simple method is reported for the preparation of graphite oxide (GO) and graphene using KCIO3/NaNO3/H2SO4 and Na2S as oxidizing agent as oxidizing and reducing agents respectively. The formation of GO and graphene have also been confirmed by X-ray diffraction studies, UV-visible, spectroscopy, FTIR and Raman spectroscopy. The morphology, surface charge characteristic and thermal stability behaviour have been studied by SEM/TEM, Zeta potential measurements, thermogravimetric analysis.     

温度对燃烧包覆LiMn2O4/ZnO及其电性能的影响

通过葡萄糖辅助低温燃烧制备ZnO包覆型LiMn2O4,利用X射线衍射仪、扫描电子显微镜、循环伏安、交流阻抗以及恒流充放电测试等手段,研究了温度对产物晶体结构、微观形貌及电化学性能的影响。XRD结果表明所有产物均为单相尖晶石型LiMn2O4结构。SEM结果表明产物的颗粒尺寸随温度的升高而增大。电化学性能测试表明400℃和500℃制备的LiMn2O4/ZnO具有相对优异的电化学性能,室温1C条件下首次放电比容量分别为119.3mAh/g、116.3mAh/g,循环100次后容量保持率分别85.6%、87.8%。尖晶石LiMn2O4电极的阻抗谱特征与温度有关,电池的电化学性能主要受电荷转移电阻(Rct)影响。     

生物源方铁锰矿吸附Cu（II）和Zn（II）的特性

利用从土壤中分离出来的Mn（II）氧化细菌Providencia sp. LLDRA6,制备和纯化生物锰氧化物。通过扫描电镜-能谱（SEM-EDS）、X射线衍射（XRD）、高分辨率透射电镜-选区电子衍射（HRTEM-SAED）、X射线光电子能谱（XPS）和比表面积测定（SSA）等手段,对生物锰氧化物进行了表征分析。研究结果表明：得到的生物锰氧化物是弱结晶的方铁锰矿（Mn2O3）,比表面积为5.740 m2/g;生物源Mn2O3对Cu（II）和Zn（II）具有较强的吸附能力,吸附最适pH均为6,吸附容量分别为89.889 mg/g和70.595 mg/g;生物源Mn2O3吸附Cu（II）和Zn（II）的动力行为均符合伪二级动力学模型,表明生物源Mn2O3吸附Cu（II）和Zn（II）的速率受化学吸附的控制;生物源Mn2O3对Cu（II）和Zn（II）的吸附均符合Langmuir等温吸附模型,表明吸附类型属于单分子层吸附。     

磁性金属有机骨架复合材料Fe3O4-COOH@MIL-101用于燃料油中含硫化合物的脱除

燃料油中含硫化合物的脱除一直是人们关注和研究的热点。采用溶剂热法原位合成磁性金属有机骨架复合材料Fe_3O_4-COOH@MIL-101,并利用XRD、SEM等技术对其进行表征。基于动态吸附实验,利用GC法分析检测,考察该复合材料对模型油中两种噻吩类硫化物苯并噻吩、二苯并噻吩的吸附脱硫效果。实验结果表明,Fe_3O_4-COOH@MIL-101复合材料兼具MIL-101和磁性微球的双重优异性能,Fe_3O_4-COOH@MIL-101复合材料对苯并噻吩和二苯并噻吩的平衡吸附量可以达到7.99 mg/g和24.60mg/g,具有较快的吸附反应动力学且符合动力学二级模型。