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11.
Nickel oxide nanoparticles decorated carbon nanotube nanocomposites(Ni O·CNT NCs)were prepared in a basic medium by using facile wet-chemical routes. The optical,morphological, and structural properties of Ni O·CNT NCs were characterized using Fourier transformed infra-red(FT-IR), Ultra-violet visible(UV/Vis) spectroscopy, field-emission scanning electron microscopy(FESEM), X-ray energy dispersed spectroscopy(XEDS), X-ray photoelectron spectroscopy(XPS), and powder X-ray diffraction(XRD) methods. Selective4-aminophenol(4-AP) chemical sensor was developed by a flat glassy carbon electrode(GCE, surface area: 0.0316 cm~2) fabricated with a thin-layer of NCs. Electrochemical responses including higher sensitivity, large dynamic range(LDR), limit of detection(LOD), and long-term stability towards 4-AP were obtained using the fabricated chemical sensors. The calibration curve was found linear(R~2= 0.914) over a wide range of 4-AP concentration(0.1 nmol/L–0.1 mol/L). In perspective of slope(2 × 10~(-5)μA/μM), LOD and sensitivity were calculated as 15.0 ± 0.1 pM and ~ 6.33 × 10~(-4)μA/(μM·cm) respectively. The synthesized Ni O·CNT NCs using a wet-chemical method is a significant route for the development of ultrasensitive and selective phenolic sensor based on nano-materials for environmental toxic substances. It is suggested that a pioneer and selective development of 4-AP sensitive sensor using Ni O·CNT NCs by a facile and reliable current vs voltage(I–V)method for the major application of toxic agents in biological, green environmental, and health-care fields in near future. 相似文献
12.
为有效抑制纳米级Pd/Fe颗粒的团聚和钝化及改善磁分离效果,以多壁碳纳米管(MWCNTs)和磁性纳米级Fe_3O_4颗粒为载体,在超声波辐照下利用液相还原法制备纳米级Pd/Fe-MWCNTs-Fe_3O_4颗粒,并采用XRD、TEM、SEM、EDX及BET表征其物性,最后以2,3-二氯联苯(2,3-DCB)为目标污染物,探究其对2,3-DCB还原脱氯的影响因素、降解机理和动力学.结果表明:制备的纳米级颗粒粒径均匀、分散性好、比表面积大;体系中纳米级Pd/Fe投加量、钯化率、纳米级Fe_3O_4投加量、MWCNTs投加量、反应温度、溶液初始pH及共存阴离子均会对2,3-DCB的降解效果产生明显影响;本研究推测出纳米级Pd/Fe-MWCNTs-Fe_3O_4体系对2,3-DCB的降解机理,发现其降解符合拟一级动力学关系. 相似文献
13.
人类活动导致大量的不可再生的磷资源流失到水环境中造成水体富营养化,磷的结晶回收对废水治理、地表水管理和可持续发展具有重要意义。采用微波-冷却-回流和超声的方法制备Ca-Fe 基磁性纳米复合材料(CaCO3-Fe3O4),通过批量吸附实验法系统探究了体系pH、接触时间、磷的初始浓度、共存离子等因素对复合材料去除水体中磷的影响规律。结果表明,CaCO3-Fe3O4纳米磁性复合材料在pH=3.0~6.0内对磷表现出良好的去除效果,对磷的最大去除容量为189.21 mg·g−1。复合材料对水体中的磷主要通过吸附-结晶耦合机制去除,在高浓度含磷废水中,磷以CaHPO4·2H2O的形式被回收。综合考虑磁分离的简易性、磷的去除容量和环境友好性,所制备的Ca-Fe基磁性复合材料在磷资源回收领域具有潜在的应用价值。 相似文献
14.
近年来,铊 (Tl) 污染事件时有发生,对饮用水源造成了严重威胁,含铊废水的高效处理刻不容缓。通过化学共沉淀法制备Fe3O4颗粒,结合水热反应、溶胶凝胶等改性方法,制备了磁性钛铁纳米颗粒 (TFNPs) 、四氧化三铁/二氧化钛核壳颗粒 (Fe3O4@TiO2) 和还原氧化石墨烯负载四氧化三铁/二氧化钛 (rGO-Fe3O4@TiO2) 复合磁性材料,考察磁性复合材料吸附、氧化去除Tl(I)的性能,并阐明其作用机制。结果表明,TFNPs、Fe3O4@TiO2和rGO-Fe3O4@TiO2单位Ti含量条件下Tl(I)最大吸附容量分别为200、271.8和440 mg-Tl·g-Ti-1。TFNPs/过硫酸盐 (PS) 、Fe3O4@TiO2/PS和rGO-Fe3O4@TiO2/PS耦合体系对Tl的去除率分别为51.7%、47.2%和88.4%,这表明rGO-Fe3O4@TiO2/PS耦合体系能够高效的去除Tl。在Tl(I)和PS混合溶液中,Fe3O4、rGO和rGO-Fe3O4@TiO2的电子供给容量 (EDC) 分别为168.2、225.4和195.4 μmol-e−·g−1,而电子接受容量 (EAC) 分别为131.4、746.8和571.3 μmol-e−·g−1,表明rGO具有优异的电子转移能力。本研究结果可为含铊废水高效处理材料的开发提供参考。 相似文献
15.
凹凸棒石/氧化锌纳米复合材料对亚甲基蓝的吸附性能 总被引:5,自引:1,他引:4
采用化学沉淀法在凹凸棒石的表面负载纳米氧化锌合成了凹凸棒石/氧化锌(ATP/ZnO)纳米复合材料.同时,研究了亚甲基蓝在纳米复合材料上的吸附行为,并从热力学和动力学角度探讨了吸附作用机理.吸附实验表明:纳米复合材料对亚甲基蓝有优异的吸附能力;纳米复合材料对亚甲基蓝的吸附热力学符合Langmuir等温吸附方程,最大吸附量可达110.50mg·g-1,吸附焓变为18.69kJ·mol-1,吸附自由能变为-33.06~-22.74kJ·mol-1,吸附熵变约为146J.mol-1.K-1,是一个自发的吸热过程;纳米复合材料对亚甲基蓝的吸附动力学符合准二级动力学方程,速率常数随着溶液初始浓度的提高而下降. 相似文献
16.
以钛酸四丁酯为钛源,甘氨酸为模板剂,水热法合成纳米TiO2/CuO复合材料,采用XRD、SEM、FT-IR、XPS、UV-VIS DRS等分析手段对TiO2/CuO复合材料的晶型结构、形貌、粒径及组成进行表征.结果表明,XRD、SEM证实TiO2/CuO复合材料由锐钛矿型TiO2和CuO组成,形貌呈花瓣薄片状纳米花球,花瓣厚约15 nm;FT-IR、XPS表明其含有Ti—O键和Cu—O键,且Ti呈+4价、Cu呈+2价;UV-VIS DR显示其在紫外-可见光区具有显著的光吸收能力.相比P25型TiO2,TiO2/CuO复合材料具有较好的光催化性能,光催化降解亚甲基蓝(MB)的效率高达85%.这可能由于TiO2/CuO复合材料具有宽的可见光区域和窄的带隙,以及CuO对电子的捕获,促进了光生电子和空穴有效分离. 相似文献
17.
通过改进的Hummers法制备氧化石墨烯(GO),再将氧化石墨烯和钛酸四丁酯作为初始反应物,利用溶剂热法制备Ti O_2/RGO纳米复合材料.利用SEM、TEM、XPS、XRD等分析手段对Ti O_2/RGO纳米复合材料进行表征,考察其在可见光照射条件下光催化还原水中Cr(Ⅵ)的效能,并对光催化还原机制进行了初步探讨.结果表明,Ti O_2/RGO复合材料的光催化还原能力与单一Ti O_2(P25)相比有了显著提高;复合材料中RGO含量、溶液p H值、催化剂投加量、Cr(Ⅵ)初始浓度均对光催化还原过程有所影响,当复合材料中RGO含量比例为2%、溶液p H值为2,催化剂投加量为40 mg时,光催化还原Cr(Ⅵ)的效率可达98%.光催化还原Cr(Ⅵ)的过程是吸附过程和光催化还原过程的共同作用结果,RGO不但提高了复合材料的吸附能力,还作为复合材料的电子导体,抑制了光生电子-空穴对的复合,增强了复合材料的光催化性能.经过5次循环使用后,复合材料的光催化还原效率仍然保持在90%左右. 相似文献
18.
Hwan-Man Park Amar K. Mohanty Lawrence T. Drzal Ellen Lee Deborah F. Mielewski Manjusri Misra 《Journal of Polymers and the Environment》2006,14(1):27-35
Injection molded nanocomposites have been successfully fabricated from cellulose acetate (CA), eco-friendly triethyl citrate
(TEC) plasticizer, and organically modified clay with and without maleic anhydride grafted cellulose acetate butyrate (CAB-g-MA)
as a compatibilizer. The effects of processing conditions such as mixing methods, pre-plasticizing times, extruder retention
times (RT) and addition of compatibilizer on the performance of these nanocomposites have been evaluated. The cellulosic plastic
with CA/TEC (80/20 wt%) was used as the polymer matrix for nanocomposite fabrication. The morphologies of these nanocomposites
were evaluated through X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. The mechanical properties
of the nanocomposites were measured and have been correlated with the XRD and TEM observations. From all of the sequential
mixing methods used, powder–powder mixing leads to the most transparent nanocomposites. Cellulosic plastic-based nanocomposites
obtained using increased pre-plasticizing times and RT showed better exfoliated structures. In the system containing compatibilizer,
the minimum retention time required for obtaining almost completely exfoliated hybrid nanocomposites was shorter than in the
system without compatibilizer. 相似文献
19.
目的研究PVDF及其氟化POSS纳米复合材料在单轴拉伸载荷下的损伤行为。方法首先依据实验结果和细观力学均匀化方法,建立纯PVDF和三种不同POSS含量PVDF/POSS纳米复合材料的颗粒掺杂有限元模型,并通过在实体单元之间嵌入可破坏的内聚力单元来模拟损伤。结果模拟得到的应力-应变关系与实验结果相吻合,证明了模拟结果的可靠性。损伤破坏的初始时间表明在破坏的初期阶段,POSS对于损伤有抑制作用,并且其效果随着POSS含量的增加而增强。损伤速度和最终的损伤面积和则表明质量分数在5%以下的POSS掺杂对于PVDF的损伤有抑制作用,并且随着POSS质量分数的增加其效果不断增强。当质量分数达到8%时,POSS的掺杂反而加速了PVDF的损伤。结论 POSS掺杂影响PVDF的损伤破坏,掺杂量对PVDF损伤破坏有抑制/促进作用,这一结果有助于理解实验所得到的力学参数的变化规律。 相似文献
20.