Low-Temperature Fabrication of Carbon Nanotube–Aluminum Composite Powders via Rotary Chemical Vapor Deposition: Process Optimization and Growth Mechanisms

This study successfully achieved the in situ synthesis of carbon nanotubes (CNTs) on aluminum powder substrates through rotating chemical vapor deposition (R-CVD) using nickel-based catalysts with acetylene as the carbon source. Through systematic parameter optimization, we elucidated the effects of catalyst loading, synthesis temperature, reaction duration, reactor rotation speed, and carrier gas ratio on the morphology, crystallinity, and yield of CNTs. Comprehensive characterization employing transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD) demonstrated that R-CVD enables low-temperature synthesis (480 °C) of CNTs with enhanced crystallinity, improved yield, and uniform distribution, exhibiting superior performance compared to conventional CVD methods. Our analysis revealed two concurrent growth mechanisms on aluminum substrates: the tip-growth and base-growth modes, wherein the proportion of the base-growth mechanism exhibited significant temperature dependence. The present work establishes an innovative strategy for the low-temperature fabrication of high-performance CNT-based composite materials.