EFFECTS OF CATALYST COMPONENTS ON CARBON NANOTUBES GROWN BY CHEMICAL VAPOR DEPOSITION

ABSTRACT

In this paper, we study the role of each of the four chemical components of a catalyst system used in growing carbon nanotubes (CNTs). Our goal is to be able to grow desirable carbon nanotubes by chemical vapor deposition (CVD), which is believed to be the most practical growth method for CNTs. The catalyst used in our process is known for inducing Y-junction CNTs. To the best of our knowledge, there has not been a thorough investigation on the importance of each chemical component used during the CNT growth. To identify the impact that each component has on CNT growth, we prepared nine samples by either excluding or doubling the amount of each component (iron nitrate, aluminum oxide, and molybdenum). We used one of three different solvents including methanol, DI water, or ethanol for the catalyst solutions. We found that 1) all three catalyst components are needed in effective growth of CNTs; 2) molybdenum has a significant role in CNT growth and y-junctions in our system; 3) the solvent has noteworthy effect on the degree of CNT crystallinity of the nanotubes and 4) the growth of multiple samples at the same time may cause interaction from one sample to the next.

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