Fabrication Of Metal-filled Carbon Nanotube Composites By Electrochemical Deposition Method

As a kind of special one dimension carbon nano-material,carbon nanotube has very unique structure, physical and chemical properties. The cavity of carbon nanotubes is a nano-scaled one-dimensional confined space. When other molecules filled into the cavity, many properties of the molecules will change obviously, such as electrical, mechanical and catalytic properties etc. The infilled carbon nanotube composites have a broad prospect of application on nano catalysis, nano transport, sensors as well as super capacitors etc. However, the traditional filling method always has many disadvantages, such as the low filling efficiency, unavoidable external coatings, the complex process, high temperature or ultra high vacuum conditions, the damage of carbon nanotubes etc. We use the aligned carbon nanotube array membranes as the starting material. The metal precursor solution(including gold chloride acid, silver nitrate and copper sulfate) spontaneous diffuse into the cavity of carbon nanotubes driven by the concentration difference. Au, Ag, Cu nano rods are then filled into the carbon nanotubes by electrochemical deposition method(including cyclic voltammetry and potentiostatic deposition). The final product are characterized by Scanning electron microscopy(SEM), transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM), Raman spectroscopy(RAMAN), Energy dispersive X-ray spectroscopy(EDAX), X-ray diffraction(XRD) etc. Au nanorods, Ag nanorods and Cu nanorods are successfully filled into carbon nanotubes with the inner diameter of only 15 nm. Nanorods grow along the long axis of carbon nanotubes and have a single crystal structure. The phenomenon fully reflects the one-dimensional template effect of carbon nanotubes. Compared with traditional methods, our method is much simpler and versatile. Also it ensures the deposition process to occur inside the carbon nanotubes with controllable nanocrystallized structures. Our method overcomes the shortcomings of the traditional method and has a good prospect. The precious metal-filled carbon nanotube array composite films have a wide range of potential applications in novel optical devices, nano-sensors and nano-catalysts.