多孔碳纳米线/MnO_2复合材料的制备及其在电化学超级电容器中的应用研究

采用化学气相沉积法(CVD),以1,2-邻二氯苯和二茂铁为前驱体批量制备高纯度多孔碳纳米线(PCNF)。采用微波法将MnO2负载在多孔碳纳米线上从而构筑MnO2/PCNF复合材料。用SEM、TEM、XRD和TGA等测试手段对所得材料进行形貌及结构分析,采用循环伏安和恒流充放电测试检测MnO2/PCNF复合材料的电容特性。实验结果表明,该复合材料比电容较高,循环性能良好,在1000圈循环测试(2A·g-1)后电容保持率为89.3%。     

杂化复合前驱体制备高分散金属镍纳米粒子的研究

以层状双金属氢氧化物/碳复合物为前驱体通过原位还原法进行了高分散纳米镍粒子的制备。通过X射线衍射（XRD）、透射电镜（TEM）、比表面积（BET）和热分析（TG-DSC）对产物结构与形貌以及催化性能进行了研究。结果表明,在惰性气氛下前驱体经还原得到高分散的纳米镍粒子,粒径约10 nm。复合前驱体中的碳作为还原剂,将层状前驱体衍生的金属氧化物原位还原为金属镍纳米粒子,还原反应进行彻底;反应温度对还原产物的相组成有重要影响。另外,纳米镍对高氯酸铵热分解显示了较好的催化作用。     

不同前驱体制备多孔氧化镁吸附剂的研究

以氢氧化镁、草酸镁、碱式碳酸镁作为前驱体,通过在不同温度下煅烧制备多孔氧化镁。考察了前驱体与制备后氧化镁结构的关系,采用热重分析仪对前驱体的热分解情况进行分析,BET、XRD、SEM表征技术对样品的形貌结构进行分析。结果表明,在一定温度下煅烧三种前驱体,制备的氧化镁均形成发达的多孔结构、具有不同的表面形貌;其中以草酸镁制成的氧化镁(MgO-3)有更大的比表面积(160.1 m²/g)与孔体积(0.68 cm2/g)与孔体积(0.68 cm³/g),吸附量为5.38%(质量分数);前驱体的平均相对分子质量越大,经煅烧后其产物具有更高的孔体积和比表面积,其结构更为发达;在较低或较高的煅烧温度下,由于前驱体很难完全分解或晶体发生烧结现象,不利于形成多孔结构。     

以碳球为模板合成氧化铈纳米空心球

以直径约为300nm的碳球为模板,通过无机物前驱体颗粒的自组装制备出CeO2/碳球复合物,煅烧去除碳球模板后,得到CeO2纳米空心球.借助透射电子显微镜、选区电子衍射、场发射扫描电子显微镜、X射线衍射、X射线光电子能谱和热重分析仪等测试手段对复合物的形貌和结构进行了表征.结果表明:产物空心球由面心立方相CeO2颗粒构成...     

MgO模板法制备多孔碳及其影响因素的研究

通过改变氧化镁前驱体和碳前驱体可制备具有高比表面积的各种多孔碳材料。近年来,关于氧化镁模板法制备多孔碳材料的研究较为活跃。本文介绍了近年来利用MgO为模板剂制备多种碳纳米材料的一些研究进展,综述了该方法的反应机理、制备条件对多孔碳材料的影响及MgO作为模板剂的优势,并对其多孔碳材料作为吸附材料、电容器的应用领域进行了展望。     

MOF衍生碳材料的制备与研究进展

多孔碳材料因其具有优良的物理化学性质,在能源、环境和催化等领域备受关注。实现多孔碳材料的结构与形貌组成可控可调,降低制备成本是它的研究重点。金属有机骨架材料(MOF)是金属离子和有机物通过配位键形成的一类新型多孔材料,在储能、催化和分离中都有广泛的应用。使用MOF作为碳的前驱体或模板制备碳材料,可以很好地继承MOF固有物理化学性质,如大比表面积、规则的孔道结构、高孔隙率、优良的吸附性能等。综述了近年来使用不同种类的MOF热解制备碳材料工作的研究进展,为今后的研究工作提供依据。     

多孔氮化硼纳米纤维的可控合成及功能化研究

为得到尺寸可控、具有大比表面积的多孔氮化硼材料,以硼酸和三聚氰胺为原料采用前驱体高温裂解法制备了多孔氮化硼纳米纤维(BNNF)。通过改变前驱体合成方式得到不同尺寸的多孔BNNF材料,探究前驱体处理方式对产物结构和形貌的影响;通过选择合适的反应气氛实现BNNF的功能化,以期对BNNF表面性质进行调控。实验结果表明,所得多孔BNNF形貌均一、尺寸可控,纤维表面存在大量孔隙且最高比表面积达到1000 m^(2)/g以上;生长过程中的氨气与氩气的混合气氛可将BNNF功能化,成功将羟基和氨基引入BNNF表面。     

芳胺废渣衍生多孔碳高效吸附去除对硝基苯酚

以工业生产过程中产生的芳胺废渣为碳前驱体，以乙酸镁作为氧化镁模板剂前驱体，采用一步法制备了N、O原位共掺杂的分级多孔碳(RPCs)。通过SEM和N2物理吸脱附对材料的形貌和孔结构进行表征,通过XPS对掺杂的N、O物种进行分析。按照质量比=1.00制备的RPC-1.00具有1427 m2/g的比表面积以及1.4713 cm3/g的孔容积。在出色的比表面积，丰富的孔结构和N、O掺杂物种的共同作用下，RPC-1.00针对对硝基苯酚的静态吸附量能够达到562.66 mg/g，固定床动态吸附量能够达到345.01 mg/g。理论计算发现，N、O原子的掺入能够增加吸附体系的色散力和静电吸引，能够有效提高吸附能。吡啶-N4和羧基结构也能产生很强的氢键作用力，提升了吸附能力。     

机械力化学法制备LiNi0.5Mn1.5O4粉体的研究

以Li2CO3,MnO2和Ni(OH)2·H2O为原料,采用机械力化学法制备锂离子层状结构正极材料LiNi0.5Mn1.5O4,采用X射线衍射,扫描电镜对其结构和形貌进行了表征.结果表明粉磨6 h可制备能在较低温度下发生固相反应的前驱体;前驱体于800℃煅烧6 h制备得到具有α-NaFeO2型层状有序结构的单相LiNi0.5Mn1.5O4.样品的首次放电容量为80 mAh·g-1.     

泡沫碳/碳纳米管复合电极材料制备及其电化学性能

在泡沫碳制备过程中,引入六水硝酸镍作为催化剂前驱体,在高温下通过过渡金属催化剂镍的催化作用制备泡沫碳/碳纳米管复合电极材料(CF/CNTs),对其结构和电化学性能进行分析表征。结果表明:CF/CNTs多孔孔壁上生成了大量碳纳米管;碳纳米管对泡沫碳孔的修饰作用提高了材料的比表面积;CF/CNTs在1 A/g电流密度下获得89.2 F/g的比电容,相比于单纯泡沫碳提升了60%。     

MnO2/MWNTs纳米材料的制备及对Cu（Ⅱ）吸附的研究

采用液相氧化还原法制二氧化锰/多壁碳纳米管(MnO2/MWNTs)复合材料,通过扫描电子显微镜(SEM)观察MnO2在MWNTs表面的负载情况,X射线衍射仪(XRD)显示MnO2是以无定形态排列在MWNTs表面。MnO2/MWNTs相比于MWNTs对Cu(Ⅱ)吸附能力提高了100%,MnO2最优负载量为30%,吸附过程的前10 min达到平衡吸附量的70%,80 min达到吸附平衡。温度升高有益于吸附。pH对吸附影响很大,吸附量随着pH的上升而增加,对Cu(Ⅱ)脱除率甚至达到了95.31%。     

La2O3对MnO2碳热还原的催化

研究了稀土氧化物La2O3作为添加剂对MnO2碳热还原的作用,通过还原实验,发现La2O3对MnO2碳热还原具有催化作用,对还原后试样进行SEM分析,认为其催化作用是通过催化试样中碳的气化反应而实现的.     

A flexible nanostructured paper of MnO NPs@MWCNTs/r-GO multilayer sandwich composite for high-performance lithium-ion batteries

Designing a high capacity and long cycle life MnO-based composite material for lithium ion batteries (LIBs) is still a great challenge because of the intrinsically low electrical conductivity and dramatic volume variations during lithiation/delithiation. In this paper, the MnO nanoparticles (MnO NPs) are recombined with multi-walled carbon nanotubes (MWCNTs) and reduced graphene oxide (r-GO) to rationally construct a novel MnO NPs@MWCNTs/r-GO multilayer sandwich structure via electrostatic interaction self-assembly and vacuum filtration processes. As a result, the MnO NPs are closely attracted in the conductive MWCNTs network, and the MWCNTs adsorbed on the surface of MnO NPs can be served as a soft and flexible carbon coating layer to self-adapt the huge volume expansion. For another, the r-GO between two MnO NPs@MWCNTs layers is the cause to form a free-standing paper, enhancing the transverse conductivity of the whole electrode simultaneously. These features will contribute to achieve excellent cycling stability and improved rate capability.     

Electrical and thermal conductivity and tensile and flexural properties: Comparison of carbon black/polycarbonate and carbon nanotube/polycarbonate resins

Adding conductive carbon fillers to thermoplastic polymers increases the resulting composite's electrical conductivity. Carbon black (CB) is very effective at increasing composite electrical conductivity at low loading levels. In this study, varying amounts (2 to 10 wt %) CB were added to polycarbonate (PC) and the resulting composites were tested for electrical conductivity (1/electrical resistivity), thermal conductivity, and tensile and flexural properties. These results were compared with prior work done for carbon nanotubes (CNT) in polycarbonate. The percolation threshold was ～ 2.3 vol % CB compared to between 0.7 and 1.4 vol % CNT. At 8 wt % filler, the CNT/PC composite had an electrical resistivity of 8 ohm‐cm compared to 122 ohm‐cm for the CB/PC composite. The addition of CB to polycarbonate increased the composite electrical and thermal conductivity and tensile and flexural modulus. The 8 wt % (5.5 vol %) CB in polycarbonate composite had a good combination of properties for semiconductive applications. Ductile tensile behavior is noted in pure polycarbonate and in samples containing up to 8 wt % CB. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Shielding effectiveness of carbon‐filled polycarbonate composites

In this project, varying amounts of three different carbons [carbon black (CB), carbon nanotubes (CNT), and graphene nanoplatelets (GNP)] were added to polycarbonate (PC). The resulting single filler composites were tested for shielding effectiveness (SE). The effects of single fillers and combinations of two different carbon fillers were studied via a factorial design. At the highest single filler loadings, the following SE results were obtained at 800 MHz: 18.9 dB for 10 wt % CB/PC, 18.4 dB for 8 wt % CNT/PC, and 6.3 dB for 15 wt % GNP/PC. The highest SE value of 21.4 dB was measured for the 5 wt % CB/5 wt % CNT/PC composite and could be used in SE applications (typically > 20 dB is needed). Statistically significant equations were developed that could be used to predict the SE of composites containing these fillers. In addition, it was determined that the composite SE is higher than what would be expected from the additive effect of each single filler for the CB/GNP/PC composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42719.     

Facile synthesis of MnO/C anode materials for lithium-ion batteries

Cubic MnO with particle sizes of ∼200 nm and ∼600 nm was synthesized by decomposition of MnCO₃. The corresponding MnO/C composite was obtained by thermal treatment of mixture of MnCO₃ and sucrose. The structure and morphology of the products were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrochemical experiments showed that the as-prepared MnO/C exhibited promising electrochemical properties, and could potentially be used as anode material in lithium-ion batteries. MnO/C delivered a reversible capacity of about 470 mAh/g after cycling 50 times, when testing at 75 mA/g. The reversible capacity, when tested at 150, 375, 755 mA/g, reached 440, 320, 235 mAh/g, respectively. The good electrochemical performance was ascribed to the smaller particle size and the efficient carbon coating on MnO.     

Effects of carbon fiber modification with multiwall CNT on the electrical conductivity and EMI shielding effectiveness of polycarbonate/carbon fiber/CNT composites

The effect of carbon fiber (CF) modification with multiwall carbon nanotube (CNT) on the electrical, mechanical, and rheological properties of the polycarbonate (PC)/CF/CNT composite was investigated. The CF and multiwall CNT (MWCNT) were treated with sulfuric acid and nitric acid (3:1 wt %) mixture, to modify the CF with the CNT. For the PC with acid-treated CNT (a-CNT) modified acid-treated CF (a-CF) (PC/a-CF/a-CNT) composite, the electrical conductivity, and the electromagnetic interference shielding effectiveness (EMI SE) showed the highest values, compared with those of the PC/a-CF and PC/a-CF/CNT composites. The EMI SE of the PC/a-CF (10 wt %)/a-CNT (0.5 wt %) composite was found to be 26 (dB at the frequency of 10.0 GHz, and the EMI SE was increased by 91.2%, compared to that of the PC/a-CF composite at the same amount of total filler content. Among the composites studied in this work, the PC/a-CF/a-CNT composite also showed the highest values of relative permittivity (ε_r) and dielectric loss factor. The above results suggest that the CF modification with the a-CNT significantly affected the electrical conductivity and EMI SE of the composite, and the hybrid fillers of the a-CNT and a-CF resulted in good electrical pathways in the PC/a-CF/a-CNT composite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47302.     

添加剂对低温烧结95氧化铝陶瓷性能的影响

采用MnO2-TiO2-CaO-La2O3复相添加剂作为氧化铝陶瓷的烧结助剂,研究了MnO2添加量对95氧化铝陶瓷烧结性能、力学性能和微观结构的影响。结果表明:当配方中MnO2含量为3.0%时,在1550℃烧结温度下制得的氧化铝陶瓷的综合性能最佳,烧结试样的体积密度达到3.76g.cm-3,试样的抗弯强度和洛氏硬度(HRA)分别达到355.22MPa和84.3。     

MnO2/MCNTs的制备及电容性能的研究

利用酸处理使多壁碳纳米管(MCNTs)表面功能化,继而结合原位化学液相沉淀法,成功制备了MnO2/MCNTs二元复合材料,并采用XRD、FTIR、SEM和TEM研究了材料的晶体结构和表面形态,运用循环伏安和交流阻抗方法研究其电化学性能.结果表明:MnO2/MCNTs二元复合材料的电容性能优于纯MnO2,且不同的MCNTs管径及长度对MnO2/MCNTs二元复合材料电化学性能及表面有影响.     

臭氧分解催化剂的制备及性能研究

用浸渍法制备了活性炭负载的复合金属氧化物催化剂并研究了其对臭氧的分解活性。在比较了MnO₂、 Co₃O₄、 NiO、Fe₂O₃、CuO等氧化物的基础上进行了复合金属氧化物/活性炭催化剂的臭氧分解活性试验，结果发现Mn-Cu系催化剂的活性高和寿命长，并且成本较低，具有良好的工业应用前景。