基于三元金属催化剂制备碳纳米管/三维石墨烯复合材料及电容性能

通过均匀沉淀法合成Ni-Mg-Al三元金属氧化物（TMO）,再通过一步化学气相沉积法（CVD）以CH₄为碳源、Ar为保护性气体,在原位还原的Ni上生长碳纳米管（CNTs）,在Mg和Al的金属氧化物上生长石墨烯（GR）,利用水热法刻蚀掉TMO,制备CNTs/三维石墨烯（3DGR）复合材料。基于CNTs与GR两种组分生长动力学的差异,通过控制Ni、Mg和Al三种金属离子的摩尔比、生长温度、生长时间,调控和优化CNTs/3DGR复合材料的结构及电容性能。借助TEM、SEM、EDS、Raman和XRD对CNTs/3DGR复合材料的结构、形貌、组分进行表征。结果表明,CNTs与GR协同作用为CNTs/3DGR复合材料提供了更多电子运输通道,可大幅提高导电性能,实现电容性能的提升,CNTs/3DGR复合材料的比电容最高可达20 F/g。      

碳纳米管修饰LaFeO3/TiO2复合材料的光催化性能与机理

采用超声辅助溶胶凝胶法制备了LaFeO₃颗粒,进一步以碳纳米管(CNTs)为基底和钛酸丁酯为前体,通过一步水热法煅烧合成CNTs/TiO₂/LaFeO₃(CTF)三元异质结光催化复合材料。通过扫描电子显微镜(SEM)、X射线衍射分析(XRD)、氮气吸附-解吸等温线(BET)、紫外-可见分光光度计(UV-Vis)、光致发光光谱(PL)等表征手段对材料的形貌与特征结构、比表面积和孔径结构以及光学特征进行了分析,并在紫外光下通过降解活性黑五(RB5)测试样品的光催化性能。结果表明,以CNTs作为载体,能够有效提升LaFeO₃/TiO₂复合材料的光催化性能。当CNTs在复合材料中的质量占比为5%时,150 W汞灯照射下RB5的50 min去除率可达99.5%。CNTs一方面通过增加复合材料的比较面积为催化反应的进行提供了更多的活性位点,更为重要的是,CNTs作为光生载流子传输的通道加快了电荷分离效率,提升了复合材料的降解能力和催化反应动力学进程。     

水热组装法制备碳纳米管网状支撑氮掺杂多孔碳材料及其储能特性研究

采用水热组装法制备了碳纳米管/氮掺杂多孔碳复合电极材料。通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、拉曼光谱(Raman)、N2吸附-脱附(BET)和X射线光电子能谱(XPS)表征了复合材料的微观形貌和结构;并采用循环伏安法、恒流充放电和交流阻抗谱测试了复合材料的储能特性。结果表明,水热组装法成功地合成了具有高比表面积(1 039m~2/g)的碳纳米管/氮掺杂多孔碳复合材料。并且该复合材料表现出优异的储能特性,在1A/g下,其比电容高达261F/g,远远高于氮掺杂多孔碳(214F/g)和碳纳米管(109F/g)的比电容;在功率密度为10 500 W/kg下其能量密度仍为53.75 Wh/kg。     

Ni (OH)2-碳纳米管-还原氧化石墨烯复合材料的制备及电化学性能

利用简单易行的一步水热法制备了Ni（OH）₂-碳纳米管-还原氧化石墨烯（Ni（OH）₂-CNTs-RGO）三元复合材料,研究了不同水热反应温度对三元复合材料性能的影响。采用XRD、FTIR、Raman、X射线光电子能谱（XPS）、SEM及TEM对Ni（OH）₂-CNTs-RGO复合材料的结构和表面微观形貌进行表征。利用循环伏安（CV）、电化学交流阻抗（EIS）和恒电流充放电测试了复合电极材料的电化学性能。研究结果表明,当反应温度为120℃时,所制备的Ni（OH）₂-CNTs-RGO复合材料具有大的比表面积和三维网状结构,复合材料中六角形的β-Ni（OH）₂纳米片和CNTs均匀分散在RGO片层表面,有效阻止了RGO的团聚。Ni（OH）₂-CNTs-RGO复合电极材料在充电倍率为0.2 C时,放电比容量达到362.8 mAh/g,5 C时放电比容量为286.2 mAh/g,仍大于Ni（OH）₂在0.2 C时的放电比容量,表明CNTs与RGO的协同作用有效提高了电极材料的导电性和活性物质的利用率,最终提升了Ni（OH）₂-CNTs-RGO复合材料的倍率性能。     

CeO2/石墨烯的合成及其在光催化制氢中的应用

采用具有丰富分级多孔结构的豆芽为模板,经水热法合成仿生形态的纳米CeO₂/石墨烯催化剂。使用XRD、拉曼光谱（Raman）、TEM、场发射扫描电子显微镜（FESEM）、紫外-可见漫反射光谱（UV-Vis/DRS）、N₂吸附-脱附仪和光解水制氢系统等分析表征手段对CeO₂/石墨烯催化剂的结构、形貌及光催化性能进行分析。结果表明,所制备的CeO₂/石墨烯光催化剂不仅继承了豆芽模板高孔隙率和大比表面积的特点,而且保持了豆芽的形态和微观特征。该催化剂是由约5.6 nm CeO₂纳米晶与具有生物形态的仿生石墨烯片层结构结合而成。制得的CeO₂/石墨烯复合材料内部存在大量由CeO₂/石墨烯催化剂纳米颗粒堆积而成的纳米孔,其孔径集中分布于15~45 nm左右,这种微观结构使CeO₂/石墨烯催化剂具有超大的比表面积,提高了催化剂对光生电子空穴对的捕获能力。由紫外-可见漫反射吸收光谱可知,CeO₂/石墨烯复合材料的可见光利用率显著增强,光解水制氢效率6 h后可达到671 μmol（h · g）^-1,远高于标样CeO₂的51.67 μmol（h · g）^-1。     

B掺杂TiO2光催化剂的制备和光催化性能

采用溶胶-凝胶法合成了B掺杂的TiO₂光催化剂,并用XRD、SEM、XPS、FT-IR、BET等手段进行了表征。结果表明,掺杂B可抑制TiO₂晶体的长大,对TiO₂表面形貌没有显著的影响,B-TiO₂催化剂的比表面积随着B离子掺杂量的提高而增大;B离子主要进入晶格间隙并与TiO₂晶体形成固溶体,以B-O-Ti结构存在。B掺杂量（质量分数）为3%时,制备出的TiO₂光催化剂对甲基橙的降解效果最好。N₂吸附-脱附结果表明,3%B-TiO₂的BET比面积为127.84 m²/g、平均孔径为10.53 nm。     

煅烧温度对In-TiO2纳米材料光催化性能的影响

采用溶胶-凝胶法合成In掺杂TiO₂纳米材料,用XRD、FT-IR以及N₂吸附-脱附等手段对其表征,研究了热处理条件对其结构和光催化性能的影响。结果表明,在不同煅烧温度制备的材料均由锐钛矿型TiO₂组成,且其表面形貌变化不大;随着煅烧温度的提高TiO₂晶粒尺寸逐渐增大,催化剂的比表面积逐渐降低,孔径逐渐增大,在400℃煅烧制得的3%In-TiO₂的比表面积为94.4 m²/g,平均孔径为10.3 nm,具有最强的光催化能力,经光照30 min后对甲基橙的光催化降解率为43.1%.     

溶液燃烧法制备Ni-Al2O3催化剂用于CO2-CH4重整研究

采用溶液燃烧法制备了Ni含量为2wt%、4wt%、6wt%、8wt%和10wt%系列催化剂, 并对反应前后催化剂进行N₂吸附-脱附、XRD、H₂-TPR、TPH、Raman、TEM和TG-DTG等表征。与等体积浸渍法(以溶液燃烧法制备的Al₂O₃为载体)制备的催化剂相比, 溶液燃烧法制备的催化剂具有较大的比表面积, 孔径分布可分为2~4.5 nm和4.5~10 nm两段, 属典型的多级孔结构; NiO高度分散在载体上, 与载体具有较强的相互作用, 这种相互作用有利于提高催化剂的稳定性。催化剂210 h稳定性试验表明, 溶液燃烧法制备的Ni含量为8wt%试样的CH₄转化率维持在90%左右, 失活速率仅为0.035%/h, 优于浸渍法制备的相同Ni含量催化剂。     

多孔结构Bi2WO6光催化剂的制备及其模拟燃油催化氧化脱硫活性

采用水热法合成了多孔结构Bi₂WO₆光催化剂, 借助X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、X射线能量色散谱(EDS)、紫外-可见漫反射(UV-Vis-DRS)、N2吸附/脱附等测试手段对样品的物相组成、形貌、比表面-孔径分布和光吸收特性等进行了表征。考察了水热温度、水热反应时间对Bi₂WO₆的形貌、比表面-孔径分布和光吸收特性影响, 并探讨了Bi₂WO₆光催化剂对模拟燃油的脱硫活性。结果表明, 在强酸性条件下水热温度和水热时间对Bi₂WO₆的形貌、比表面积和催化活性影响显著, 190℃水热反应2 h所得Bi₂WO₆为新颖的鸟巢状微晶, 且鸟巢状Bi₂WO₆由片层状二级结构组装而成。XRD和EDS表明, 鸟巢状结构的Bi₂WO₆为正交晶系, 纯度较高。N₂吸附-脱附测试结果表明, 鸟巢状Bi₂WO₆具有多孔结构, 孔主要分布在10 nm, 比表面积大约为17.49 m²/g。催化活性测试结果表明, 三维介孔结构Bi₂WO₆具有较好的模拟燃油脱硫效果, 在空气流量为100 mL/min, 催化剂加入量为1.2 g/L, 可见光照射180 min, 模拟汽油脱硫率高达91.2%, 且催化剂的稳定性能较好。     

CNTs/TiO2复合物制备及光催化性能研究

在不使用表面活性剂的情况下, 采用溶胶-凝胶法成功制备CNTs/TiO₂复合物, 利用XRD、TEM、HRTEM和SAED对样品的结构和形貌进行了表征。选取亚甲基蓝溶液为目标降解物, 利用紫外-可见(UV-Vis)分光光度计考察了CNTs/TiO₂复合物的光催化活性, 系统研究了CNTs掺杂量对催化降解效率的影响。实验结果表明: 经450℃煅烧, 锐钛矿相TiO₂通过C-O-Ti键均匀地涂覆在CNTs表面, TiO₂颗粒尺寸约16 nm。CNTs/TiO₂复合物光催化活性明显高于纯TiO₂, 当CNTs掺杂量为1wt%时, CNTs/TiO₂复合物对亚甲基蓝的催化降解效率最高, 比纯TiO₂提高11.7%。     

羟基磷灰石/碳纳米管复合材料的制备及其细胞毒性研究

利用原位合成法制备出羟基磷灰石/碳纳米管复合材料,采用XRD、TEM对其成分及结构进行了表征;采用MTT法和细胞形态分析研究了该复合材料对L-929细胞增殖活性的影响及细胞毒性反应,从而对其进行初步的生物相容性评价。结果表明,复合材料由羟基磷灰石和碳纳米管两相构成,纳米级的短棒状羟基磷灰石均匀吸附在碳纳米管表面,与之形成较强的界面结合;不同浓度的复合材料浸提液在不同时间点培养的细胞均正常增殖,其细胞毒性均在1级以下,符合国家医用生物材料的细胞毒性要求。     

Additive manufacturing of CNTs/PLA composites and the correlation between microstructure and functional properties

Owing to the facile,low cost,rapid,personalization characters,3D printing method has been one of the most attractive additive manufacturing processes in medicine,airplane,packaging and printing areas.In this work,a series of carbon nanotubes/polylactic acid(CNTs/PLA) composites were prepared through the combination of molten co-extrusion and 3D printing processes.The orientation and dispersion of CNTs in PLA matrix were investigated to explore the impact of 3D printing process on the morphology of CNTs/PLA composites via transmission electron microscopy,field emission scanning electron microscopy and Raman spectroscopy.X-ray diffractometer,differential scanning calorimetry,and thermal gravity analysis were employed to study the crystal structure and thermal properties of the composites.In addition,the electrical conductivity of the prepared specimen revealed that the orientation of CNTs in PLA might enhance the conductivity of the composite.It was found that 3D printing process was beneficial to increasing the purity of CNTs,electrical conductivity and mechanical properties of CNTs/PLA composites.     

Efficient strategy to Cu/Si catalyst into vertically aligned carbon nanotubes with bamboo shape by CVD technique

Bamboo-shaped vertically aligned carbon nanotubes (bs-VACNTs) were fabricated on Cu/Si catalyst by chemical vapour deposition (CVD) technique under the atmospheric pressure. The catalytic material (Cu/Si) played a vital role in attaining bs-VACNTs, which is synthesized by drop cast method in a cost-effective manner. Using this catalytic support, we have achieved the tip growth bs-VACNTs at low temperature with well graphitization. The as-grown carbon material was then characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) analyzer, high-resolution transmission electron microscope (HRTEM) and Raman spectroscopy. XRD technique confirms the formation of hexagonal graphitic carbon planes of carbon nanotubes (CNTs). The surface morphology of the material was characterized by SEM, which clearly infer vertically aligned CNTs. The nature, diameter and crystallinity were noticed by HRTEM and Raman spectroscopy, respectively. Further, we have also studied the electrochemical properties of the bs-VACNTs and it seems to be proved as highly electroconductive when compared to multi-walled carbon nanotubes (MWCNTs).     

Effect of a multiscale reinforcement by carbon fiber surface treatment with graphene oxide/carbon nanotubes on the mechanical properties of reinforced carbon/carbon composites

An effective carbon fiber/graphene oxide/carbon nanotubes (CF-GO-CNTs) multiscale reinforcement was prepared by co-grafting carbon nanotubes (CNTs) and graphene oxide (GO) onto the carbon fiber surface. The effects of surface modification on the properties of carbon fiber (CF) and the resulting composites was investigated systematically. The GO and CNTs were chemically grafted on the carbon fiber surface as a uniform coating, which could significantly increase the polar functional groups and surface energy of carbon fiber. In addition, the GO and CNTs co-grafted on the carbon fiber surface could improve interlaminar shear strength of the resulting composites by 48.12% and the interfacial shear strength of the resulting composites by 83.39%. The presence of GO and CNTs could significantly enhance both the area and wettability of fiber surface, leading to great increase in the mechanical properties of GO/CNTs/carbon fiber reinforced composites.     

Surface modified graphite nanosheets used as adsorbent to remove 1,2-dichlorobenzene from water

The surface of graphite nanosheets (GNs) prepared by wet ball milling from expanded graphite (EG) was surface modified during the preparation process. The SEM images shown were employed to analyze the morphology of surface modified graphite nanosheets. The XPS date and Raman spectroscopy show that the milling process gives graphene surface more defects and phenolic groups compared to that of expanded graphite and graphite nanosheets. It was found that after ball milling, the surface modified GNs can be used as an effective adsorbent to remove 1,2-dichlorobenzene from water. Their adsorption capacity reaches 28.3 mg/g, which is comparable to that of carbon nanotubes (CNTs).     

自组装和分散可逆的碳纳米管圆片

通过加热碳纳米管和强酸的混合物,使碳纳米管的憎水表面发生氧化.加热含经处理的碳纳米管的悬浮液,使之脱水,得到自组装的碳纳米管圆片,该圆片可直接分散.扫描电镜图显示该圆片由局部规则排列的碳纳米管构成;红外光谱和光电子谱分析表明在化学处理过程中,碳纳米管的表面产生了含氧官能团;虽然拉曼谱测出处理过程增加了缺陷,但是X射线衍射结果表明碳纳米管类似石墨的层状结构得到保留;同时研究了经处理的碳纳米管的热稳定性.这种自组装且可分散的碳纳米管圆片为研究碳纳米管结构材料和碳纳米管复合材料提供了有效途径.     

Effects of amino group on the properties of carbon nanotubes

The surfaces of multi-walled carbon nanotubes were grafted with amino functional groups by reacting acyl-chloride-functionalized carbon nanotubes (CNTs) with hexamethylene diamine, which improves the surfactivity of CNTs. The dispersity, surface morphology, and thermogravimetry of acid-treated and amino-functionalized CNTs were investigated. Amino-functionalized CNTs were added into epoxy resin to analyze the effects of amino functional groups on the properties of resin composites. It was found that the properties of CNTs, such as morphology and scale, were not affected by amino functional groups, but the dispersity in water was highly improved. Amino-functionalized CNTs are better dispersed in resin matrix, and the mechanical properties of composites are improved significantly, whereas the conductivity of composites is not enhanced as expected.     

碳纳米管/PLA复合材料制备及性能

采用溶液共混法制备纯化和酸化碳纳米管(CNTs)/PLA(聚乳酸)复合膜, 并对CNTs的分散性以及材料的结晶形态、 电性能和降解性能进行了研究。结果表明, 通过SEM观察到经过酸化处理的CNTs能较好地分散在PLA基体中; 在偏光显微镜下能观察到CNTs起到成核剂的作用, 明显细化了晶粒; 加入少量的酸化CNTs能够提高CNTs/PLA复合材料导电性, 体积电阻率下降了7个数量级; 同时, 酸化CNTs能够提高CNTs/PLA复合材料的降解性。     

Preparation and modification of carbon nanotubes

Carbon nanotubes (CNTs) were prepared by the catalytic decomposition of methane at 680 °C for 120 min, using nickel oxide–silica binary aerogels as the catalyst. The morphological structure of CNTs was investigated by transmission electron microscopy (TEM), X-ray Diffraction (XRD) and Raman spectroscopy. The results revealed that CNTs with diameter 40–60 nm showed high quality, uniform diameter and high length/diameter ratio, the wall structure of CNTs was similar with that of highly oriented pyrolytic graphite (HOPG), and some metal catalyst particles were encapsulated at the tip of CNTs. Different methods were compared to modify CNTs. Investigated by TEM, XRD, Raman spectroscopy and nitrogen adsorption/desorption for modified CNTs, it was confirmed that after modification treatment by immersion in diluted HNO₃ solution with ultrasonic and then milling by ball at a high velocity, the metal catalyst particles at the tip of CNTs disappeared, the unique cylinder wall structure remained, the CNT length became short, the cap at the tip of nanotube was opened, and thus the internal surface area could be effectively used, leading to the increase of the specific surface area and pore volume. This technique is relatively simple and effective for modifying CNTs which can be scaled up for industrial applications.     

碳包覆NiO纳米颗粒的制备与性能

采用直流电弧放电等离子体技术成功制备了碳包覆NiO(NiO@C)纳米颗粒,并对样品的形貌、晶体结构、粒度、比表面积和孔结构采用高分辨透射电子显微镜、X射线衍射、X射线能量色散分析谱仪、拉曼散射光谱和N_2吸-脱附等测试手段进行了分析。实验结果表明:直流电弧等离子体技术制备的NiO@C纳米颗粒具有典型的核壳结构,内核为面心立方结构的NiO纳米颗粒,外壳为碳层。颗粒形貌主要为立方体结构,粒度均匀,分散性良好,粒径分布在30~70nm范围,平均粒径为50nm,外壳碳层的厚度为5nm。NiO@C纳米颗粒BET比表面积为28m~2/g,等效直径为46nm,与TEM和XRD测得的结果基本一致。Raman光谱说明样品中碳包覆层的石墨化程度较低,发生了红移现象。