Structural Changes in Iron Oxide and Gold Catalysts during Nucleation of Carbon Nanotubes Studied by <i>In Situ</i> Transmission Electron Microscopy

Tang, Dai‐Ming; Liu, C.; Yu, Wanjing; Zhang, L. L.; Hou, Peng‐Xiang; Li, J. C.; Li, F.; Bando, Yoshio; Golberg, Dmitri; Cheng, Huikai

doi:10.1021/nn403927y

Cited by 54 publications

(50 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, we found that the as-formed caps always match well the dimension of the NPs, which is in good agreement with previous studies on iron and iron carbide catalysts. 20,21 TEM images showing the structural changes of a Fc−S@ CNT with applied voltage are given in Figure 3. In Figure 3a, we can see that NPs with diameters of ∼10 nm were formed inside of the CNT nanoreactor after a few minutes of Joule heating, which is in sharp contrast to the small NPs observed in the Fc@CNT shown in Figure 2.…”

Section: Section: Surfaces Interfaces Porous Materials and Catalysismentioning

confidence: 99%

In Situ TEM Observations on the Sulfur-Assisted Catalytic Growth of Single-Wall Carbon Nanotubes

Zhang

Hou

et al. 2014

J. Phys. Chem. Lett.

Self Cite

View full text Add to dashboard Cite

The effect of sulfur on the catalytic nucleation and growth of single-wall carbon nanotubes (SWCNTs) from an iron catalyst was investigated in situ by transmission electron microscopy (TEM). The catalyst precursor of ferrocene and growth promoter of sulfur were selectively loaded inside of the hollow core of multiwall CNTs with open ends, which served as a nanoreactor powered by applying a voltage inside of the chamber of a TEM. It was found that a SWCNT nucleated and grew perpendicularly from a region of the catalyst nanoparticle surface, instead of the normal tangential growth that occurs with no sulfur addition. Our in situ TEM observation combined with CVD growth studies suggests that sulfur functions to promote the nucleation and growth of SWCNTs by forming inhomogeneous local active sites and modifying the interface bonding between catalysts and precipitated graphitic layers, so that carbon caps can be lifted off from the catalyst particle.

show abstract

Section: Section: Surfaces Interfaces Porous Materials and Catalysismentioning

confidence: 99%

In Situ TEM Observations on the Sulfur-Assisted Catalytic Growth of Single-Wall Carbon Nanotubes

Zhang

Hou

et al. 2014

J. Phys. Chem. Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, Au, Ag, and Cu have low solubility of carbon [26][27][28]. No chemical reactions or phase transitions of Au particles were observed by in situ transmission electron microscopy during MWCNT growth [29]. Nevertheless, these elements also produce SWCNTs.…”

Section: Swcnt Growth Mechanism From Gold Nanoparticlesmentioning

confidence: 99%

Gold Nanoparticles as the Catalyst of Single-Walled Carbon Nanotube Synthesis

Homma

2014

Catalysts

View full text Add to dashboard Cite

Gold nanoparticles have been proven to act as efficient catalysts for chemical reactions, such as oxidation and hydrogen production. In this review we focus on a different aspect of the catalysis of gold nanoparticles; single-walled carbon nanotube (SWCNT) synthesis. This is not a traditional meaning of catalytic reaction, but SWCNTs cannot be synthesized without nanoparticles. Previously, gold was considered as unsuitable metal species as the catalyst of SWCNT synthesis. However, gold nanoparticles with diameters smaller than 5 nm were found to effectively produce SWCNTs. We discuss the catalysis of gold and related metals for SWCNT synthesis in comparison with conventional catalysts, such as iron, cobalt, and nickel.

show abstract

“…Such studies comprise the use of iron oxide and gold catalysts for the formation of carbon nanotubes [278], the analysis of unsupported Au particles deposited on Si [279], the Au assisted growth of MgO crystals [280], and Au assisted growth of Ge nanowires [281]. Different Au-based alloys were studied by TEM or E-TEM; these studies could be extended to their behaviour under catalytic conditions.…”

Section: Perspectivesmentioning

confidence: 99%

Dynamic Processes on Gold-Based Catalysts Followed by Environmental Microscopies

et al. 2017

View full text Add to dashboard Cite

Abstract:Since the early discovery of the catalytic activity of gold at low temperature, there has been a growing interest in Au and Au-based catalysis for a new class of applications. The complexity of the catalysts currently used ranges from single crystal to 3D structured materials. To improve the efficiency of such catalysts, a better understanding of the catalytic process is required, from both the kinetic and material viewpoints. The understanding of such processes can be achieved using environmental imaging techniques allowing the observation of catalytic processes under reaction conditions, so as to study the systems in conditions as close as possible to industrial conditions. This review focuses on the description of catalytic processes occurring on Au-based catalysts with selected in situ imaging techniques, i.e., PEEM/LEEM, FIM/FEM and E-TEM, allowing a wide range of pressure and material complexity to be covered. These techniques, among others, are applied to unravel the presence of spatiotemporal behaviours, study mass transport and phase separation, determine activation energies of elementary steps, observe the morphological changes of supported nanoparticles, and finally correlate the surface composition with the catalytic reactivity.

show abstract

Structural Changes in Iron Oxide and Gold Catalysts during Nucleation of Carbon Nanotubes Studied by In Situ Transmission Electron Microscopy

Cited by 54 publications

References 62 publications

In Situ TEM Observations on the Sulfur-Assisted Catalytic Growth of Single-Wall Carbon Nanotubes

In Situ TEM Observations on the Sulfur-Assisted Catalytic Growth of Single-Wall Carbon Nanotubes

Gold Nanoparticles as the Catalyst of Single-Walled Carbon Nanotube Synthesis

Dynamic Processes on Gold-Based Catalysts Followed by Environmental Microscopies

Contact Info

Product

Resources

About