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Low temperature and cost-effective growth of vertically aligned carbon nanofibers using spin-coated polymer-stabilized palladium nanocatalysts

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ABSTRACT

We describe a fast and cost-effective process for the growth of carbon nanofibers (CNFs) at a temperature compatible with complementary metal oxide semiconductor technology, using highly stable polymer–Pd nanohybrid colloidal solutions of palladium catalyst nanoparticles (NPs). Two polymer–Pd nanohybrids, namely poly(lauryl methacrylate)-block-poly((2-acetoacetoxy)ethyl methacrylate)/Pd (LauMAx-b-AEMAy/Pd) and polyvinylpyrrolidone/Pd were prepared in organic solvents and spin-coated onto silicon substrates. Subsequently, vertically aligned CNFs were grown on these NPs by plasma enhanced chemical vapor deposition at different temperatures. The electrical properties of the grown CNFs were evaluated using an electrochemical method, commonly used for the characterization of supercapacitors. The results show that the polymer–Pd nanohybrid solutions offer the optimum size range of palladium catalyst NPs enabling the growth of CNFs at temperatures as low as 350 °C. Furthermore, the CNFs grown at such a low temperature are vertically aligned similar to the CNFs grown at 550 °C. Finally the capacitive behavior of these CNFs was similar to that of the CNFs grown at high temperature assuring the same electrical properties thus enabling their usage in different applications such as on-chip capacitors, interconnects, thermal heat sink and energy storage solutions.

No MeSH data available.


SEM images of CNFs grown by DC-PECVD for 2 h at different temperatures on palladium NPs using various PVP–Pd colloidal solutions given as (a) PVP:Pd 38:1, growth at 550 °C. (b) PVP:Pd 18:1, growth at 550 °C. (c) PVP:Pd 9:1, growth at 550 °C. (d) PVP:Pd 9:1, growth at 390 °C.
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Figure 2: SEM images of CNFs grown by DC-PECVD for 2 h at different temperatures on palladium NPs using various PVP–Pd colloidal solutions given as (a) PVP:Pd 38:1, growth at 550 °C. (b) PVP:Pd 18:1, growth at 550 °C. (c) PVP:Pd 9:1, growth at 550 °C. (d) PVP:Pd 9:1, growth at 390 °C.

Mentions: A representative TEM image of the solution A system is provided in figure 1. As seen in the image, tiny, spherical palladium NPs can be visualized with average diameters in the range 2.3 ± 0.3 nm. The presence of a few larger aggregates may be due to drying-induced aggregation during TEM sample preparation. In the case of the PVP/Pd systems, HRTEM analysis revealed that the palladium NPs are nanocrystals with average diameters below 10 nm. The crystalline planes (111) and (200) of palladium NP could be visualized with characteristic interplanar distances of 2.27 and 1.97 Å, respectively [26]. Tilted view and top view (inset on each picture) SEM images of CNFs grown at 550 °C using three PVP/Pd solutions having different metallic (palladium) content are shown in figures 2(a)–(c) whereas SEM images of the CNFs grown at 390 °C using the PVP/Pd (1:9) solution is provided in figure 2(d).


Low temperature and cost-effective growth of vertically aligned carbon nanofibers using spin-coated polymer-stabilized palladium nanocatalysts
SEM images of CNFs grown by DC-PECVD for 2 h at different temperatures on palladium NPs using various PVP–Pd colloidal solutions given as (a) PVP:Pd 38:1, growth at 550 °C. (b) PVP:Pd 18:1, growth at 550 °C. (c) PVP:Pd 9:1, growth at 550 °C. (d) PVP:Pd 9:1, growth at 390 °C.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036482&req=5

Figure 2: SEM images of CNFs grown by DC-PECVD for 2 h at different temperatures on palladium NPs using various PVP–Pd colloidal solutions given as (a) PVP:Pd 38:1, growth at 550 °C. (b) PVP:Pd 18:1, growth at 550 °C. (c) PVP:Pd 9:1, growth at 550 °C. (d) PVP:Pd 9:1, growth at 390 °C.
Mentions: A representative TEM image of the solution A system is provided in figure 1. As seen in the image, tiny, spherical palladium NPs can be visualized with average diameters in the range 2.3 ± 0.3 nm. The presence of a few larger aggregates may be due to drying-induced aggregation during TEM sample preparation. In the case of the PVP/Pd systems, HRTEM analysis revealed that the palladium NPs are nanocrystals with average diameters below 10 nm. The crystalline planes (111) and (200) of palladium NP could be visualized with characteristic interplanar distances of 2.27 and 1.97 Å, respectively [26]. Tilted view and top view (inset on each picture) SEM images of CNFs grown at 550 °C using three PVP/Pd solutions having different metallic (palladium) content are shown in figures 2(a)–(c) whereas SEM images of the CNFs grown at 390 °C using the PVP/Pd (1:9) solution is provided in figure 2(d).

View Article: PubMed Central - PubMed

ABSTRACT

We describe a fast and cost-effective process for the growth of carbon nanofibers (CNFs) at a temperature compatible with complementary metal oxide semiconductor technology, using highly stable polymer–Pd nanohybrid colloidal solutions of palladium catalyst nanoparticles (NPs). Two polymer–Pd nanohybrids, namely poly(lauryl methacrylate)-block-poly((2-acetoacetoxy)ethyl methacrylate)/Pd (LauMAx-b-AEMAy/Pd) and polyvinylpyrrolidone/Pd were prepared in organic solvents and spin-coated onto silicon substrates. Subsequently, vertically aligned CNFs were grown on these NPs by plasma enhanced chemical vapor deposition at different temperatures. The electrical properties of the grown CNFs were evaluated using an electrochemical method, commonly used for the characterization of supercapacitors. The results show that the polymer–Pd nanohybrid solutions offer the optimum size range of palladium catalyst NPs enabling the growth of CNFs at temperatures as low as 350 °C. Furthermore, the CNFs grown at such a low temperature are vertically aligned similar to the CNFs grown at 550 °C. Finally the capacitive behavior of these CNFs was similar to that of the CNFs grown at high temperature assuring the same electrical properties thus enabling their usage in different applications such as on-chip capacitors, interconnects, thermal heat sink and energy storage solutions.

No MeSH data available.