Water vapor-induced structure modification of vertically-aligned carbon nanotube arrays and successive thin film coating for enhanced field emission properties

Hawsawi, Adil; Jo, Sung Ho; Kang, Jung Su; Park, Kyu-Chang; Jeong, Goo‐Hwan

doi:10.1016/j.cap.2020.01.017

Cited by 6 publications

(2 citation statements)

References 36 publications

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“…Moreover, the I D /I G value increases from 1.17 for the as-synthesized CNTs to 1.41, due to the plasma treatment. Similar values were reported by A. Hawsawi et al, who used a similar exposure time and temperature for the water vapor plasma treatment of vertically aligned CNTs, for the subsequent deposition of W and SiO 2 particles to improve their field emission characteristics [28]. Herein, the plasma-induced defects acted as anchoring sites for the next PED.…”

Section: Resultssupporting

confidence: 77%

Pulsed Electro Decoration of Carbon Nanotubes with FexZn1−xS

Bjelajac,

Florea,

Zamfir

et al. 2024

Coatings

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A wide ranging scientific interest in developing new and simple preparation methods for highly catalytic bimetallic sulfides provided our motivation to explore the possibility of using the pulsed electrodeposition technique for the decoration of a carbon nanotubes forest. The carbon nanotubes were obtained using the hot-filament chemical vapor deposition technique. A non-thermal plasma treatment enabled the controlled creation of defects on the carbon nanotubes’ surface. These defects served as anchoring sites for the subsequent deposition of Fe and Zn nanoparticles using the pulsed electrodeposition technique. Our findings showed that only in the case of Fe deposition prior to Zn provided the formation of FeZn bimetallic-based nanoparticles, with Zn present mainly on the outer surface of the Fe core. To induce sulfurization, a thermal treatment in sulfur vapor was conducted at 500 °C, and the obtained heterostructure consisted of Fe0.3Zn0.7S as the main phase, with the minor presence of ZnS and S residues, which was deduced from the XRD results. This study provides thorough imaging of the process, presenting for each preparation step SEM/HR-TEM findings, coupled with EDS chemical analyses. The samples were tested for photocatalytic degradation of methyl blue dye to demonstrate the photoactive behavior of the heterostructure.

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Section: Resultssupporting

confidence: 77%

Pulsed Electro Decoration of Carbon Nanotubes with FexZn1−xS

Bjelajac,

Florea,

Zamfir

et al. 2024

Coatings

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“…Because FE phenomenon is based on electron tunneling, we estimated field enhancement factor ( β ) using the Fowler-Nordheim (FN) plot from Figure 8 . The β can be calculated as following relation [ 17 , 18 ].

where, B is the FN constant (6.83 × 10 3 V eV −3/2 μm −1 ), φ is a work function of CNTs (5 eV) [ 19 ], D is distance between CNTs and anode (500 μm) and slope of the F–N plot.…”

Section: Resultsmentioning

confidence: 99%

Investigation of Early Stage of Carbon Nanotube Growth on Plasma-Pretreated Inconel Plates and Comparison with Other Superalloys as Substrates

Shin

Lee

et al. 2020

Nanomaterials

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We investigate the early stage of carbon nanotube (CNTs) growth on Inconel 600 to address the effect of pretreatments such as annealing and plasma pretreatment on growth behavior. In addition, we compare the growth results to other Ni-based superalloys including Invar 42 and Hastelloy C276. The growth substrates were prepared using mechanical polish, thermal annealing and plasma pretreatment. The air annealing was performed at 725 °C for 10 min and plasma pretreatment was subsequently undergone with 10.5 W at 500 °C for 30 min. The annealed and plasma-pretreated substrates exhibited different surface morphologies on the surface and enhanced growth behavior of CNT was observed from the region of particulate surface. The optimized growth temperature, which produces the highest CNT height, was determined at 525 °C for Ni and Inconel 600 and 625 °C for Invar 42 and Hastelloy C276 substrates. The difference of optimal growth temperature is expected to the existence of high temperature elements such as Mn or Mo in the alloys. X-ray diffraction spectroscopy revealed that the formation of roughened oxide layers caused by the pretreatments would promote the nucleation and growth of the CNTs.

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