活性炭/碳纳米管复合电极电吸附机理研究

按活性炭∶碳纳米管∶PVDF=7.2∶0.8∶2质量比制备活性炭/碳纳米管复合电极,并对其构成的EST模块进行吸附动力学、等温吸附和电迁移拟合研究,分析其吸附机理。结果表明,准一级反应动力学模型和Langmuir模型能够很好的拟合、描述活性炭/碳纳米管复合电极在EST脱盐过程中的吸附机理,说明电吸附速率只与一种反应物的浓度有关且是单离子层吸附,EST吸附过程中离子的电迁移率随迁移时间的变化趋势可以用指数形式的方程很好的拟合。     

活性炭纤维电吸附处理含盐溶液吸附特性研究

以活性炭纤维为电极材料处理NaCl模拟水,研究了电吸附过程中电极电压、流量、含盐量等对脱盐效果的影响,同时分析了电吸附对水溶液中离子的吸附动力学特性,并以吸附等温线探讨双电层对水溶液中离子的吸附能力。结果表明,对于特定的电吸附装置,当电源施加电压为2.2 V,304不锈钢板的极板电压为1.77 V,流量为15mL/min时,电吸附的平均脱盐率为41.16%。电吸附过程符合Langmuir单分子层吸附等温模型,施加电压为2.2 V时,Langmuir吸附常数为0.088,饱和吸附容量为5.84 mg/g。准一级反应动力学模型、Elovich方程、二级反应动力学模型拟合程度均不高。相比较,Elovich方程拟合效果较好。     

活性炭电极电吸附甲基橙废水研究

自制一种新型粘结剂(NB),并用此粘结剂与活性炭粉末(AC)混合制备活性炭电极(ACE)。利用数码相机、扫描电子显微镜(SEM)及傅立叶红外光谱仪(FTIR)对电极表面形貌、亲水性及电极表面的官能团进行分析,并用此电极进行电吸附甲基橙(MO)的操作条件及动力学研究。结果表明,电极亲水性好,并含有大量含氧官能团;在MO初始质量浓度为40 mg/L、电解质(Na2SO4)质量浓度5.0 mg/L、pH为6.5、温度为25℃时,600 mV电压下,MO的去除率达到88.35%,较开路时提高了17.18%;动力学分析表明,在AC电极上电吸附MO溶液符合Lagergren 1级吸附动力学模型。     

浓混酸改性碳纳米管涂层电极的电吸附脱盐研究

采用浓H2SO4与浓HNO3(体积比1∶1)的混酸对碳纳米管进行除杂、开口和改性,用碳纳米管与PVDF(质量比8∶2)制备改性碳纳米管涂层电极,研究其脱盐效果。研究表明,经浓混酸处理后,碳纳米管的比表面积降低了5.75%,分散性更好,能够长时间、均匀地悬浮在溶液中,有利于其在电极表面均匀涂布;碳纳米管涂层电极的饱和吸附量提高了40.39%。     

活性炭电极改性及电吸附除盐性能研究

以m(果壳活性炭)∶m(酚醛树脂)∶m(乌洛托品)∶m(石墨粉)=70:29:0.5:0.5制得活性炭电极,采用比表面积及孔径分析仪(BET)、X射线衍射分析仪(XRD)、电化学工作站分析电极的表面性质、孔径分布及电化学性能.结果表明:在电吸附过程中,经过物理化学改性后的活性炭电极对NaCl的单位吸附量达到7.14 mg/g,物理改性电极的单位吸附量为5.86 mg/g,相比高出21.84％.经拟合均符合伪二级动力学方程.通过物理化学法改性的活性炭电极具有更好的电吸附性能和优良的重复利用性.     

改性活性炭/碳纳米管复合电极脱盐性能研究

采用改性CNT*作为CDI电极导电剂,制备AC*/CNT*复合电极,考察其脱盐性能。利用BET、FTIR和TEM对AC或CNT的表面结构、官能团种类和分散性进行分析。利用电化学工作站和SEM对复合电极的比电容、阻抗和表面形貌进行分析。结果表明,通过改性,AC*的比表面积达到672.48 m2/g,增加了29.43%;CNT*的比表面积为117.39 m2/g,下降了9.94%,但其分散性得到有效改善。根据循环伏安测试和静态脱盐实验结果 ,按AC*∶CNT*∶PVDF=7.2∶0.8∶2质量比制备的电极效果最好,比电容高达130.48 F/g,比吸附量达到7.29 mg/g。     

石油焦基高比表面积活性炭电吸附脱盐性能的研究

采用石油焦为原料,以KOH为活化剂,制得高比表面积活性炭,比表面和孔容远高于常规活性炭,孔径分布和常规活性炭相似.以高比表面积活性炭作为电吸附电极,考察其在NaCl溶液中的电吸附性能,并对话性炭电极电吸附的影响因素进行研究.结果表明,活性炭电极的电吸附性能主要受比表面积和孔容的影响,高比表面积和大孔容的活性炭单位电吸附...     

ACF电吸附过程动力学特性和脱盐影响因素试验研究

近年来,国家强化了对各类污水的治理力度和排放标准。其中,工业废水具有较大的节水与回用潜能,急需一种高效低成本的脱盐技术。目前电吸附技术凭借其能耗低、无需添加药剂、除盐效率高等特点在水处理领域广泛应用。采用电吸附技术实现废水快速脱盐主要从脱盐速度提高和高通量产水2个方面入手。由于动力学因素决定了离子在吸附剂内部的吸附速率,吸附容量决定除盐率,因此探究影响电吸附过程动力学特性和脱盐影响因素是该技术的关键。以活性炭纤维为电极材料,在自制的板式电吸附装置进行多组电吸附试验,研究进样浓度、外加电压、进样液pH值和温度对其除盐效率和饱和吸附容量的影响,并对不同电压、不同浓度下的电吸附动力学结果进行拟合。动力学研究表明:电压是离子吸附速率的主要因素;电压<0.8 V时,适用于准二级动力学方程,电压>0.8 V后适用一级动力学模型,电压越大离子吸附速率越快。等温吸附模型研究表明:增大电压和初始浓度可以提高电吸附容量,吸附过程适用Langmuir吸附等温模型来描述。弱酸性条件更有利于电吸附除盐性能的提高;温度升高对离子吸附有抑制作用,室温为最佳试验温度。     

活性炭电极对不同阳离子电吸附行为的研究

自制活性炭电极,并用于不同含量的KCl、CdCl_2、CuCl_2和FeCl_3溶液电吸附行为研究.结果表明,多价离子吸附速率和吸附容量大,但脱附率低;单价离子吸附速率和吸附容量小,但脱附率高;同价态离子,离子半径越小的离子越容易被吸附.各离子在活性炭电极上的电吸附,均符合2级动力学方程,速率常数K与电压U关系符合指数函数,在相同电压下,吸附速率常数K(Fe~(3+))>K(Cu~(2+))>K(Cd~(2+))>K(K~+);吸附等温线均符合Langmuir等温式,活性炭电极的最大吸附量q_m与操作电压U线性相关,在相同电压下,活性炭电极的最大吸附容量q_m(Fe~(3+))>q_m(Cu~(2+))>q_m(Cd~(2+))>q_m(K~+).循环伏安和交流阻抗进一步验证了电吸附试验结果.     

板式活性炭纤维电极电吸附除盐实验研究

自行制作板式活性炭纤维电极电吸附除盐装置,通过单因素实验分析方法,研究了电极板间距、电压、进水流速和进水浓度对未改性的活性炭纤维电极电吸附除盐的影响效果。结果表明,最佳电压2.0 V,电极板间距1 mm,进水流量10 mL/min,进水电导率1 000μS/cm条件下,电导率去除率最高,在40%以上,显示了活性炭纤维电极在电吸附除盐方面较好的应用前景。     

纳米活性炭/锌锰复合电极材料的制备及性能

使用溶胶-凝胶法合成锌掺杂二氧化锰的纳米晶电极材料,将其与干式振动滚压法制备的纳米活性炭混合制成超级电容器所需的片状电极。纳米活性炭材料为类球状颗粒,粒径约为50 nm,且为微孔和中孔并存的狭缝结构;制备的锌掺杂二氧化锰纳米晶材料为中孔占优的孔隙结构,含有纳米锌和氧化锌的成分,经XRD测试和比表面分析,得到此纳米晶材料的平均粒径小于30 nm。分析显示,经滚压振动研磨改性的纳米活性炭与10%纳米晶锌锰材料混合的电极材料具有较好的电容性能,比电容达到299 F.g-1。     

碳纳米管/聚苯胺复合材料修饰电极制备及应用研究进展

综述了碳纳米管(CNTs)/聚苯胺(PANI)复合材料修饰电极的层层组装法和电共沉积法等制备方法,详细介绍了国内外关于CNTs/PANI复合材料修饰电极在抗坏血酸、葡萄糖、酚类及多酚类化合物、氨基甲酸酯类农药检测方面的研究进展并对该修饰电极的应用和发展前景进行了展望。     

碳纳米管/聚苯胺复合材料修饰电极制备及应用研究进展

综述了碳纳米管(CNTs)/聚苯胺(PANI)复合材料修饰电极的层层组装法和电共沉积法等制备方法,详细介绍了国内外关于CNTs/PANI复合材料修饰电极在抗坏血酸、葡萄糖、酚类及多酚类化合物、氨基甲酸酯类农药检测方面的研究进展并对该修饰电极的应用和发展前景进行了展望。     

Electrochemical determination diethylstilbestrol by a single-walled carbon nanotube/platinum nanoparticle composite film electrode

Platinum nanoparticles (Pt_nano) were prepared and used in combination with single-wall carbon nanotube (SWNT) for fabricating electrochemical sensors with remarkably improved sensitivity toward diethylstilbestrol (DES). The glassy carbon (GC) electrode modified with SWNT/Pt_nano composite film exhibited excellent electrochemical behaviors toward the redox of DES. Compared with the bare GC electrode and SWNTs film modified GC electrode, the redox peak currents at the SWNTs/Pt_nano composite film modified GC electrode was enhanced greatly. The experimental parameters, which influence the peak current of DES, were optimized. Under optimal conditions, a linear response of DES was obtained in the range from 1.0 × 10⁻⁷ to 2.0 × 10⁻⁵ mol L⁻¹ (R = 0.997) and with a limit of detect (LOD) of 1.5 × 10⁻⁸ mol L⁻¹. The proposed procedure was successfully applied to determine the active ingredient in the DES tablet with satisfactory results.     

Polyaniline/carbon nanotube composite Schottky contacts

Schottky contacts were fabricated on composites of high molecular weight polyaniline and pristine multiwalled carbon nanotubes. Physical and electrical characteristics of these organic composite materials were studied by using atomic force microscopy (AFM), scanning electron microscopy (SEM), and electrical measurements. The RMS surface roughness of the composite films was found to be 4 nm. From the IV characteristics of these composite devices, it appears that the current follows Ohm's law at lower voltages and Child's law at higher voltages, indicating a space‐charge‐limited emission mechanism in the presence of a distribution of shallow traps.     

Enhanced electrosorption capacity for lead ion removal with polypyrrole and air‐plasma activated carbon nanotube composite electrode

Polypyrrole (PPy) and air‐plasma activated carbon nanotube (CNT) composites (P‐CNT‐PPy) prepared via in situ chemical oxidative polymerization are studied to improve the electrosorption capacity of CNT‐based electrodes for the removal of lead ions. For comparison, the PPy prepared on the CNTs without plasma activation is labeled as CNT/PPy. The morphology of the composite was observed by scanning electron microscopy (SEM), and pore structures were studied by N₂ adsorption‐desorption isotherms. The electrochemical capacitance properties of the composite were measured by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge‐discharge in lead solutions. With plasma‐activation, the specific surface area of the P‐CNT‐PPy composite is larger than that of CNT/PPy. Additionally, the P‐CNT‐PPy composites exhibit excellent electrochemical performance in lead solution, with a higher specific capacitance and smaller charge transfer resistance than that of CNT/PPy. XPS elemental analysis and electrosorption and regeneration results show that the electrosorption and desorption process is reversible under a voltage of 450 mV. The electrosorption kinetics of P‐CNT‐PPy electrodes abide by pseudo‐second‐order model reaction. The lead ion electrosorption experiments agree with the Langmuir model, and the equilibrium electrosorption capacity of the P‐CNT‐PPy electrodes is 3.6 and 1.3 times higher than that of the CNT and CNT/PPy, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41793.     

NaCl adsorption in multi-walled carbon nanotube/active carbon combination electrode

In this paper, we proposed a new process for fabricating electrochemical double layer capacitors employing active carbon and multi-walled carbon nanotubes to adsorb Na⁺ and Cl^- from NaCl solution. Due to their unique mesoporosity, active carbons have high ability to desalt NaCl solution. But they have many defects such as high electrical resistance, high-energy consumption and low intensity. Since carbon nanotube is a new material which has high intensity and low resistance, we can composite the merits of active carbon and carbon nanotube and develop carbon nanotube/active carbon materials combination electrode. It was tested that when carbon nanotube content in carbon materials is 10%, the characteristics of combination electrode is the best for us to desalt brackish water because of their high desalination characterization and low energy consumption. Though there are a few technical problems to be solved, our results show a promising technique for desalting salt water.     

Advanced carbon nanotube/polymer composite infrared sensors

We demonstrate that both single-walled carbon nanotube (SWCNT) types and nanotube-matrix polymer-nanotube (CNT-P-CNT) junctions have profound impact on electro-optical properties of SWCNT/polymer composites. Composite IR sensors based on CoMoCAT^®-produced SWCNTs (SWCNTs_CoMoCAT) significantly outperform those based on HiPco^®-produced SWCNTs (SWCNTs_HiPco). Higher semiconducting nanotube concentration in a SWCNT material is critical to enhance the photo effect of IR light on SWCNT/polymer nanocomposites, whereas CNT-P-CNT junctions play a dominant role in the thermal effect of IR light on supported SWCNT/polymer composite films.     

Well-dispersed single-walled carbon nanotube/polyaniline composite films

Single-walled carbon nanotube (SWNT)/polyaniline (PANI) composite films with good uniformity and dispersion were prepared by electrochemical polymerization of aniline containing well-dissolved SWNTs. The results of atomic force microscopy (AFM) and UV-Vis adsorption spectroscopy show that aniline can be used to solubilize SWNTs via formation of donor-acceptor complexes. The electrochemical deposition of SWNT-aniline solutions have been investigated by cyclic voltammetry. The results show that SWNT-based aniline solutions exhibit a drastic increase in peak current within the potential scanning region. The doping effect of SWNTs on PANI films was investigated by electrochemistry and FTIR spectroscopy. The results indicate that the enhanced electroactivity and conductivity of the SWNT/PANI composite films may be due to the strong interaction between SWNTs and PANI, which facilitates the effective degree of electron delocalization.