An investigation on the effects of hydrogen (H2) gas dilution on the morphology and growth of carbon nanowalls (CNWs) decorated carbon nanotubes (CNTs) by hot-wire r.f. plasma enhanced chemical vapour deposition technique is presented. With the assistance of nickel nanoparticle catalyst, CNWs decorated CNTs formed only under the presence of 25% of H2 gas, relative to the methane (CH4) gas precursor. By varying the amount of H2 incorporated with CH4, the role of H2 dilution in the development of CNWs decorated CNTs was studied. Based on the FESEM and HRTEM results, it is hypothesized that H2 density and relative carbon radical concentration are the important parameters for the deposition of CNWs decorated CNTs. The effect of H2 dilution on the formation of CNWs decorated CNTs is presented.
On the role of activation mode in the plasma- and hot filaments-enhanced catalytic chemical vapour deposition of vertically aligned carbon nanotubes
