在氩气氛下生长的C60薄膜的结构与特性

采用惰性气氛蒸发法制备C60薄膜,用原子力显微镜(AFM)、X射线衍射(XRD)、红外光谱(IR)及紫外-可见光谱研究了在氩(Ar)气氛下生长的C60薄膜的表面形貌、结构及光吸收特性.AFM测量表明在Ar气氛下生长的Ceo薄膜的表面生长岛更尖锐,并且有较大直径的表面粒子.由紫外-可见光吸收谱测量发现Ar气氛下生长的C60薄膜的强度和吸收峰位置与在真空下生长的C60薄膜比较有大的红移.可求出在Ar气氛下生长的C60薄膜的光学禁带宽度Eg一2.24eV,比在真空下生长的C6o薄膜禁带宽度(2.02eV)要大.与真空下生长的C60薄膜比较,Ar气氛下生长的Cso薄膜的红外谱没有变化,但X射线衍射表明其结构从面心立方(fcc)相变成fcc相与六角密堆(hcp)相的混合相.     

水热法合成氧化镍-二氧化硅催化剂及其用于碳纳米管的制备

以硝酸镍和正硅酸乙酯为原料，制得Ni(OH)2／SiO2二元胶体，经水热晶化法和常压干燥法分别合成了纳米级氧化镍-二氧化硅复合粉体催化剂}用这两种催化剂在相同催化裂解条件下分别制得了多壁碳纳米管；采用XRD和TEM等测试手段对两种催化剂物相、形貌及由两种催化剂制得的碳纳米管形态、收率及纯度作了比较，结果表明：水热晶化法比常压干燥法合成的催化剂粉体颗粒粒径小(为10～20nm），分散性好，催化活性高，使得所制得的碳纳米管管径小(为10～16nm)、分布窄、纯度和收率都相对较高；同时对用不同水热反应温度合成的催化剂(物相不同)制备碳纳米管进行了研究。     

Diameter-Controlled Growth of Carbon Nanotubes Through Pyrolysis of Acetylene Using Rare Earth Alloy as Catalyst in Hydrogen

Carbonnanotubes[1] (CNTs)havenovelquasione dimensionhollowstructurewithsmalldensity ,largeratioofsurfacetovolume ,highmechanicalstrength ,goodconductivityandchemicalstability .CNTshavepotentialapplicationsinmakingcatalystcarrier ,fabricatingnanoelectronics ,manufacturinghigh densityenergystoragematerial ,constructinghigh strengthcompositematerial ,andpreparingelec tromagneticwaveabsorptionmaterial[2～ 8] .InordertostudytheperformanceandapplicationofCNTs ,itisimportanttofindouthowtosynthesiz…     

Structural and electrochemical performance of additives-doped α-Ni(OH)2

The additives-doped α-nickel hydroxides were prepared by supersonic co-precipitation method. The crystal structure and grain size of the prepared samples were characterized by X-ray diffraction (XRD) and Particle size distribution (PSD), respectively. Cyclic voltammetry (CV) tests show that Al-Co-Y doped Ni(OH)2 has better reaction reversibility, higher proton diffusion coefficient than those of Al-Co doped Ni(OH)2. Al-Co-Y doped Ni(OH)2 also has lower charge-transfer resistance as shown by electrochemical impedance spectroscopy (EIS). Charge/discharge tests show that the discharge capacity of Al-Co-Y doped Ni(OH)2 reaches 328 mAh/g at 0.2 C and 306 mAh/g at 0.5 C, while Al-Co doped Ni(OH)2 can only discharge a capacity of 308 mAh/g at 0.2 C and 267 mAh/g at 0.5 C.     

Influence of Sodium Carbonate Amount on Crystalline Phase and Structure Stability for Doping Nickel Hydroxide

Alpha nickel hydroxide has better performances than commercial beta nickel hydroxide. However, the main defect is that α-phase is difficult to synthesize and easily transformed to β-phase Ni(OH)_2 upon aging in a strong alkaline solution. In this study, the Al-Co, Al-Yb, Yb-Co and Al-Yb-Co multiple doping was used respectively. By controlling the amount of sodium carbonate, the α-Ni(OH)_2 was prepared by ultrasonic-assisted precipitation. And the influence of sodium carbonate on the crystalline phase and structure stability for alpha nickel hydroxide was studied. The results demonstrate that, with increasing amount, the biphase nickel hydroxide transforms to pure alpha nickel hydroxide gradually, and the structure stability is also improved. When the amount of sodium carbonate is 2 g, the sample still keeps α-Ni(OH)_2 after being aged for 30 days, for Al-Yb-Co-Ni(OH)_2. And when the amount is less than 2 g, the phase transformations exist in the samples with different extents. These results demonstrated that the amount of sodium carbonate is a critical factor to maintain the structural stability of α-Ni(OH)_2.     

气体压强对氮气氛下制备的C60纳米薄膜形貌和光学性质的影响

用扫描电镜、双光束紫外 可见分光光度计和椭偏仪研究了在氮气 (N2 )氛下制备的C6 0 薄膜的表面形貌及光吸收特性。研究发现 ,薄膜表面粒子粒径随气压的增大而增大 ,表面结晶现象也随气压增大而明显 ;与真空中制备的C6 0 薄膜比较 ,发现其紫外 可见吸收的相对强度明显不同 ,吸收峰位红移 ;并且随着氮气压强的增加吸收峰位红移增加。对氮气氛下C6 0 薄膜的形成机理及光吸收特性进行了讨论     

Synthesis of Fullerene by Pyrolysis of Acetylene in Thermal HF-Plasma

Carbon soot containing fullerene was continuously produced in volume by pyrolyzing acetylene in thermal HF-Plasma. The characteristics of the carbon soot and C60 were analyzed by thtransmission electron microscopy, UV/visible, IR and Raman spectroscopy. The results show that the main ingredients of the carbon soot with size of about 25 nm are amorphous carbon, graphite and fullerene. The fullerene yield in carbon soot is about 2.5 g·h^-1. Compared with the graphite arc discharge method, the acetylene thermal plasma method is a preferential one for synthesis of fullerene.     

在氩气氛下生长的C_(60)薄膜的结构与特性

采用惰性气氛蒸发法制备 C6 0 薄膜 ,用原子力显微镜 (AFM)、X射线衍射 (XRD)、红外光谱 (IR)及紫外 -可见光谱研究了在氩 (Ar)气氛下生长的 C6 0 薄膜的表面形貌、结构及光吸收特性 .AFM测量表明在 Ar气氛下生长的C6 0 薄膜的表面生长岛更尖锐 ,并且有较大直径的表面粒子 .由紫外 -可见光吸收谱测量发现 Ar气氛下生长的 C6 0 薄膜的强度和吸收峰位置与在真空下生长的 C6 0 薄膜比较有大的红移 .可求出在 Ar气氛下生长的 C6 0 薄膜的光学禁带宽度 Eg=2 .2 4e V,比在真空下生长的 C6 0 薄膜禁带宽度 (2 .0 2 e V)要大 .与真空下生长的 C6 0 薄膜比较     

纳米添加剂对镍氢电池正极电化学性能的影响

采用制备的纳米氧化锌(均匀沉淀法)和碳纳米管(化学气相沉积法)作为正极添加剂,掺杂制备两种不同正极极片。研究了正极中添加不同含量在不同放电制度下对MH-Ni电池电化学性能的影响。结果表明,在30 mA/g恒电流密度放电条件下,添加纳米氧化锌(ZnO)的模拟电池有助于提高放电性能,第80次循环时添加量为2%的放电比容量最高为259.2 mAh/g;但在60 mA/g恒电流密度放电条件下,模拟电池中添加碳纳米管(CNTs)的作用比较明显,添加量为1%CNTs的在第80次循环时放电比容量为260.3 mAh/g,而且放电平台比较平稳。     

乙炔等离子体热解法制备C60的研究

用乙炔高频等离子体热解法连续大批量合成含富勒烯的碳灰。用透射电镜（TEM）、X射线衍射（XRD）、紫外－可见光谱（UV－Vis）、红外光谱（IR）等测试手段对碳灰进行了分析研究，并测定了富勒烯C60的产率为2．5g／h。