Preparation and Structural Studies of Metal/Carbon Nano Composites using Metal Acetylides

虽然我们的研究取得了进展，直到去年在生产，如金属纳米点阵列，金属纳米片，金属纳米电缆，我们已经成功地制备了一种创新的碳材料，介孔碳纳米枝（MCND）在2007年。碳枝晶在每100-150 nm处表现出分支，其典型尺寸为100至几百μm。该主体由许多介孔和微孔单元组成，其具有2-3层石墨烯片的壁。这些石墨状多孔枝晶是由乙炔银化合物向银和碳的放热分凝反应引起的爆炸性银蒸发产生的。爆炸性的银沸腾加热碳，产生石墨结构。由于银填充的空间超过了原始枝晶的90%，残留的碳胞只占据了不到10%的空间，并保持了乙炔化物的枝晶形状。这意味着树突由与原始材料一样大的空房间组成。根据反应时间的不同，圆柱体的尺寸在20 - 50 nm之间变化，但分支之间的长度总是在100- 150 nm范围内。BET表面积的典型值宽至1，500 m2/g。用MCND电极制作的超级电容器的有效功率密度超过了DOE的目标值。我们还发现碳包覆的铜纳米线的电导率在1atm下吸附氧气时增加了两倍。这种材料可以在低温下用作氧传感器。

While our study achieved the progress until the last year in producing such as metal nano-dot arrays, metal nanosheets, metal-nanocables, we have succeeded in preparing an innovative carbon material, Mesoporous Carbon Nano Dendrites (MCND) in 2007. The carbon dendrite shows branching at every 100-150 nm and its typical size amounts to 100 to several 100μm. The body is composed of numerous meso-porous and micro-porous cells with the walls of 2-3 layers of graphene sheets. These graphitic porous dendrites are produced by the explosive silver vaporization due to the exothermic segregation reaction of silver acetylides to silver and arbons. The explosive silver boiling heats the carbon up to produce the graphitic structure. Since the space filled by the silver amounts to more than 90% of the original dendrite, the residual carbon cells just occupy the space less than 10% with keeping the dendrite shape of the acetylide. This means that the dendrites are composed of empty rooms as big as the original materials. The size of the cylinder varies from 20nm to 50nm depending on the reaction time, but the length between the branches is always in the range of 100-150nm. A typical value of the BET surface area is as wide as 1, 500 m2/g. The available power density obtained by a super capacitor with the MCND electrodes exceeds the target value given by DOE.We also discover that the electric conductivity of the copper nanowires sheathed in carbon increases upon the adsorption of oxygen at 1 atm as big as two times. This material can be used as an oxygen sensor at low temperatures.