A new approach for orientation-controlled growth of CNTs: an in-depth analysis on the role of oxygen plasma treatment to catalyst

Tripathi, Nishant; Islam, S. S.

doi:10.1007/s13204-017-0549-z

Cited by 18 publications

(8 citation statements)

References 20 publications

(13 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tripathi and Islam found that a 10 min oxygen plasma treatment of iron catalyst on a P-type silicon (100) substrate can significantly increase the nucleation sites of carbon nanotubes (CNTs), which can change the orientation of CNTs. When the CNT growth was carried out over the substrate, not treated with plasma, a horizontal network of CNTs was formed.…”

Section: Surface Treatmentmentioning

confidence: 99%

Catalyst Preparation with Plasmas: How Does It Work?

et al. 2018

View full text Add to dashboard Cite

Catalyst preparation with plasmas is increasingly attracting interest. A plasma is a partially ionized gas, consisting of electrons, ions, molecules, radicals, photons, and excited species, which are all active species for catalyst preparation and treatment. Under the influence of plasma, nucleation and crystal growth in catalyst preparation can be very different from those in the conventional thermal approach. Some thermodynamically unfavorable reactions can easily take place with plasmas. Compounds such as sulfides, nitrides, and phosphides that are produced under harsh conditions can be synthesized by plasma under mild conditions. Plasmas can produce catalysts with smaller particle sizes and controllable structure. Plasma is also a facile tool for reduction, oxidation, doping, etching, coating, alloy formation, surface treatment, and surface cleaning in a simple and direct way. A rapid and convenient plasma template removal has thus been established for zeolite synthesis. It can operate at room temperature and allows the catalyst preparation on temperature-sensitive supporting materials. Plasma is typically effective for the production of various catalysts on metallic substrates. In addition, plasma-prepared transition-metal catalysts show enhanced low-temperature activity with improved stability. This provides a useful model catalyst for further improvement of industrial catalysts. In this review, we aim to summarize the recent advances in catalyst preparation with plasmas. The present understanding of plasma-based catalyst preparation is discussed. The challenges and future development are addressed.

show abstract

Section: Surface Treatmentmentioning

confidence: 99%

Catalyst Preparation with Plasmas: How Does It Work?

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Cold plasma modification has also been employed to the further growth of materials [251,253,254] or enhance the performance of the catalytic materials [255,256]. Yu et al [251] adopted an RF water plasma to modify a 30 nm thick SiO 2 film in SiO 2 /Si wafer at 250 kHz, 30 W, and 0.62 Torr for 20 min to produce SiO 2 nanoparticles as the metal-free catalytic materials on the substrate.…”

Section: Cold Plasma Modification Of Catalytic Materialsmentioning

confidence: 99%

Cold plasma treatment of catalytic materials: a review

Di¹,

Zhang²,

Zhang³

et al. 2021

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Catalytic materials play important roles in chemical, energy, and environmental fields. The exhaustion of fossil fuels and the resulting deteriorative environment have become worldwide problems to be solved urgently. Therefore, treatment of catalytic materials by a green process is required for a sustainable future, and the atom efficiency of the catalytic materials should be improved at the same time. Cold plasma is rich in high-energy electrons and active species, and the gas temperature can be close to room temperature. It has been proved to be a fast, facile, and environmentally friendly novel method for treating catalytic materials, and has aroused increasing research interests. First, plasma treatment can achieve the reduction, deposition, combination, and decomposition of active components during the preparation of catalytic materials. The fast, low-temperature plasma process with a strong electric field in it leads to different types of nucleation and crystal growth compared to conventional thermal methods. Correspondingly, the synthesized catalytic materials generally possess smaller particle sizes and controlled structure depending on the plasma processing parameters and the materials to be treated, which can enhance their activity and stability. Second, plasma treatment can achieve the modification, doping, etching, and exfoliation of the catalytic materials, which can tune the surface properties and electronic structures of the catalytic materials to expose more active sites. Third, plasma treatment can regenerate deactivated catalytic materials by removing the carbon deposits or other poisons, and reconstruction of the destroyed structure. This work reviews the current status of research on cold plasma treatment of catalytic materials. The focus is on physical and chemical processes during plasma processing, the processing mechanism of the catalytic materials, as well as the future challenges in this filed.

show abstract

“…CNT growth in the presence of green catalyst at temperature (575°C) is another unexpected achievement. The normal temperature requirement for MWNTs growth in CVD with catalyst such as transition metal catalysts, or SiO 2 or ceramic catalyst, reported in the literature are around 700-1200°C, required for creating nucleation sites (Tripathi et al 2014a;Liu et al 2013;Tripathi et al 2015;Uthayakumar and Sivasubramanian 2013;Chang and Esei 1998;Zhang et al 2012;Tripathi et al 2015;Tripathi and Islam 2017). But in our case activated nucleation sites are already present in activated carbon produced from green catalyst.…”

Section: Cvd Processmentioning

confidence: 56%

Synthesis of carbon nanotubes using green plant extract as catalyst: unconventional concept and its realization

Tripathi

Pavelyev

2017

Appl Nanosci

Self Cite

View full text Add to dashboard Cite

Green catalyst derived from plants, a cheap and abundant natural source, is used for the synthesis of multiwalled carbon nanotubes (MWNTs). The concept is unconventional and practically realized into existence by simple CVD growth while keeping away the potential hazards caused by metal catalyst on environment and living organisms. The notable points to mention of such growth are: (1) grown CNTs are free from toxic metal catalyst, (2) low growth temperature (575°C) required and produced high yield vis-à-vis any other catalyst used so far reported, and (3) no need of expensive and complex systems for its synthesis. Besides, growth of SWNT as well as carbon nano-belts with hollow rectangular cross-section is observed when growth temperature increased to 800°C, specifically, for the wall-nut extract. The samples were characterized by microscopic and spectroscopic analysis and the results verified our study. The present work provides innovative technique and may open up new avenues for CNTs synthesis and its applications.

show abstract

A new approach for orientation-controlled growth of CNTs: an in-depth analysis on the role of oxygen plasma treatment to catalyst

Cited by 18 publications

References 20 publications

Catalyst Preparation with Plasmas: How Does It Work?

Catalyst Preparation with Plasmas: How Does It Work?

Cold plasma treatment of catalytic materials: a review

Synthesis of carbon nanotubes using green plant extract as catalyst: unconventional concept and its realization

Contact Info

Product

Resources

About