Field emission from diamond-coated multiwalled carbon nanotube “teepee” structures

Abstract

Dense arrays of vertically aligned multiwalled carbon nanotubes (MWCNTs) have been seeded with a nanodiamond suspension in methanol using electrospray deposition. This treatment caused the tips of groups of 20-40 MWCNTs to stick together forming structures resembling "teepees." Subsequent short chemical vapour deposition experiments using standard diamond-growing conditions allowed the nanodiamond seeds to grow into a thin continuous film, locking the teepee structures into this shape. Field emission tests show that these diamond-coated carbon nanotubes (CNTs) teepees retain the low threshold voltage of the uncoated CNTs but with greatly improved emission stability and lifetime. V

Atomic H-Induced Mo2C Hybrid as an Active and Stable Bifunctional Electrocatalyst

“…Scanning electron microscopy (SEM) was carried out to study the morphology of VA-GNR before and after atomic H treatment (Figure b–e). As shown in Figure b and Figures S1–S2, the unzipped VA-GNR have clumps of tips that meet together, forming structures resembling Native American “teepees” . The teepees are distributed with enough open space to permit the Mo particles to pass through the VA-GNR bundles and disperse on the surface of the VA-GNR.…”

“…As shown in Figure 1b and Figure S1-S2, the unzipped VA-GNR have clumps of tips that meet together, forming structures resembling Native American "teepees". 32 The teepees are distributed with enough open space to permit the Mo particles to pass through the VA-GNR bundles and disperse on the surface of the VA-GNR. Based on imaging, there is limited agglomeration of the Mo, which appears as a film to the eye (Supporting Information, Figure S3).…”

Carbon nanotubes overgrown and ingrown with nanocrystalline diamond deposited by different CVD plasma systems

“…Nowadays, fundamental research on the combination of CNTs and diamond is very popular and progressing rapidly. This new class of hybrid nanomaterial has many possible applications, including its use in field emission devices, thermoelectric generators, and electrodes for the electrochemical redox cell or as a functional component of highly sensitive biosensors .…”

Enhancing the stability of microplasma device utilizing diamond coated carbon nanotubes as cathode materials

“…[10][11][12] However, the short lifetime and the poor stability of the CNTs emitters, especially in a plasma environment, have been the major barriers averting their profitable viability. 13,14 To surmount this drawback, CNTs have been combined with other field emitting materials by depositing thin films on CNTs, [15][16][17] decorating CNTs with nanoparticles, 18 or by making composites of CNTs. 19,20 On the other hand, diamond has the most strongly bonded crystal structure and has excellent physical and chemical properties, which makes it a potential electron source with higher lifetime and reliability.…”

“…It is interesting to integrate the high robustness of diamond films and marvelous electron field emission (EFE) properties of CNTs to yield highly stable electron sources. Actually, many attempts have been made to couple the diamond and CNTs, 16,17,[21][22][23][24] but the results are still not satisfactory that is probably due to the difficulty in integration of the two materials. Moreover, among the diamond films developed for EFE applications, the ones with hybrid granular structure, the HiD films, which were obtained by growing the nanocrystalline diamond (NCD) on ultrananocrystalline diamond (UNCD) seeding layer, possess marvelous EFE properties 25,26 and are most appropriate for the development of diamond-CNTs composite EFE emitters for microplasma applications.…”