Effect of NH3 gas ratio on the formation of nitrogen-doped carbon nanotubes using thermal chemical vapor deposition

Kim, Chang-duk; Lee, Hyeong-Rag; Kim, Hong Tak

doi:10.1016/j.matchemphys.2016.08.033

Cited by 22 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Contrary to the plasma treatment with NH 3 exclusively, pyridinic-N seems to dominate the N level in the N-rGO nanosheets (see Figure S3). Furthermore, typical N-doped graphene and N-rGO reported by previous literatures are apparently dominated by pyridinic-N or pyrrolic-N. ,− Thus, the successful increment of quaternary-N by our simple plasma method could provide an alternative way to alter the electronics structure of the graphene material.…”

Section: Resultsmentioning

confidence: 63%

Wafer-Scale Fabrication of Nitrogen-Doped Reduced Graphene Oxide with Enhanced Quaternary-N for High-Performance Photodetection

Haniff

Ariffin

Hafiz

et al. 2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

We demonstrated a simple and scalable fabrication route of a nitrogen-doped reduced graphene oxide (N-rGO) photodetector on an 8 in. wafer-scale. The N-rGO was prepared through in situ plasma treatment in an acetylene-ammonia atmosphere to achieve an n-type semiconductor with substantial formation of quaternary-N substituted into the graphene lattice. The morphology, structural, chemical composition, and electrical properties of the N-rGO were carefully characterized and used for the device fabrication. The N-rGO devices were fabricated in a simple metal−semiconductor−metal structure with unconventional metal-on-bottom configuration to promote high-performance photodetection. The N-rGO devices exhibited enhanced photoresponsivity as high as 0.68 A W −1 at 1.0 V, which is about 2 orders of magnitude higher compared to a pristine graphene and wide-band photoinduced response from the visible to the near-infrared region with increasing sensitivity in the order of 785, 632.8, and 473 nm excitation wavelengths. We also further demonstrated a symmetric characteristic of the photoinduced response to any position of local laser excitation with respect to the electrodes. The excellent features of waferscale N-rGO devices suggest a promising route to merge the current silicon technology and two-dimensional materials for future optoelectronic devices.

show abstract

Section: Resultsmentioning

confidence: 63%

Wafer-Scale Fabrication of Nitrogen-Doped Reduced Graphene Oxide with Enhanced Quaternary-N for High-Performance Photodetection

Haniff

Ariffin

Hafiz

et al. 2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…Among these synthesis methods, CVD has been used to synthesize 3D metal and nitrogen-doped graphene/CNT hybrids because of its highly tunable nature compared to traditional thermal pyrolysis, making it preferable for constructing specific structures. However, there are a few drawbacks or challenges in conventional CVD methods for 3D carbon synthesis: (1) multistep CVD syntheses are typically used to generate CNTs and graphene; − (2) high energy input is always involved due to the high-temperature condition (usually 1000 °C) required to synthesize graphene by CVD; , (3) an additional step of acid washing is usually required to remove bulk metal catalysts from the substrate after CVD; (4) N-doping is typically achieved by gaseous nitrogen precursors, e.g., ammonia (NH 3 ) or acetonitrile (CH 3 CN), and the N doping level is lower (less than 3%) compared to traditional solid nitrogen sources. − As a result, few reports in the literature have demonstrated high-performing 3D carbon structures for the CO 2 RR synthesized by a CVD method. Therefore, there is still a high demand for a facile and low-cost method to synthesize 3D M-N-C catalysts for efficient CO 2 RR application.…”

Section: Introductionmentioning

confidence: 99%

One-Step Chemical Vapor Deposition Synthesis of Hierarchical Ni and N Co-Doped Carbon Nanosheet/Nanotube Hybrids for Efficient Electrochemical CO₂ Reduction at Commercially Viable Current Densities

et al. 2021

View full text Add to dashboard Cite

Carbon catalysts with metal and nitrogen dopants hold significant promises for an electrochemical CO2 reduction reaction (CO2RR). However, the fabrication of these carbon catalysts normally requires an energy-intensive synthesis process. Traditionally, 2D graphene and 1D carbon nanotubes (CNTs) are the most widely used carbon supports, but graphene tends to aggregate and CNTs suffer from low density of active sites on the surface. In this work, we developed a 3D hybrid carbon nanosheet/nanotube catalyst with nickel (Ni) and nitrogen (N) co-doped active sites for the CO2RR by a one-step chemical vapor deposition (CVD) method. Both single atomic sites and nanoparticles of Ni were observed on the hybrids, but the Ni nanoparticles were encapsulated by graphitic carbon layers during the CVD process, and as a result, the competing hydrogen evolution reaction was suppressed and high CO selectivity was achieved. The as-prepared catalyst with 20 min CVD delivered a stable CO Faradaic efficiency of 91% with a partial current density of 28.9 mA/cm2 at −0.74 V in an H-cell setup. The same catalyst achieved a commercially viable current density of 600 mA/cm2 in a flow cell with CO selectivity above 85%, at an applied voltage of −2.0 V vs reversible hydrogen electrode without iR compensation. To the best of our knowledge, these results are among the best performances in the literature in terms of both current density and CO selectivity for the CO2RR by carbon-based catalysts. Furthermore, catalysts developed in this work are synthesized at a moderate temperature without any acid/oxidant pretreatment or post-washing. The energy-efficient and environmentally benign synthesis and the significantly high performance of catalysts are essential to future large-scale CO2RR applications.

show abstract

“…Decreased CNF graphitization increases the D-band intensity in the CNFs produced. The D-band intensity is directly related to the sp 3 carbon bond, representing defects in the hexagonal carbon sp 2 structure . Therefore, the magnitude of the defect in the hexagonal carbon structures of CNFs can be measured by calculating the intensity ratio of I D / I G .…”

Section: Resultsmentioning

confidence: 99%

Magnetic Carbon Nanofibers Prepared with Ni and Ni/Graphitic Carbon Nanoparticle Catalysts for Glycine Detection Using Surface-Enhanced Raman Spectroscopy

Prasiwi

Saraswati

Anwar

et al. 2021

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

The combination of a noble metal with a carbon nanomaterial for surface-enhanced Raman scattering (SERS) has been commonly explored using metal-outside surface decoration to achieve a dominant electromagnetic enhancement mechanism. The use of a non-noble metal encapsulated inside carbon nanofibers (CNFs) for SERS is an interesting field of research because its heterogeneous structure possibly amplifies charge transfer, which induces the chemical enhancement mechanismbased SERS phenomena. This study investigated the use of magnetic CNFs in SERS for detecting small amino acid glycine as an analyte model. The magnetic CNFs were successfully synthesized via chemical vapor deposition (CVD) using Ni and carbon-wrapped Ni nanoparticles (Ni/C) as catalysts. The Ni/C catalyst was prepared via submerged arc discharge in a medium of ethanol/H 2 O. The CVD process was performed at different temperatures with Ar/C 2 H 2 gases, beginning with a synthesis temperature of 600 °C. The morphological analysis of the CVD product showed that the products had a typical structure of CNF-encapsulated Ni nanoparticles. However, Ni and Ni/C catalysts grew CNFs in different features. Ni/C-CNFs had a homogeneous diameter size and more crystalline graphitic carbon layers than Ni-CNFs. All produced CNFs possessed magnetic properties that correlated well with the Ni amount and its crystallization. The Raman intensity of glycine with the SERS substrate of dispersed CNFs grown using both catalysts was significantly higher than the normal Raman signal. The enhancement factor (EF) using the Ni/C-CNF substrate was higher (∼6 × 10 3 ) than that of the Ni-CNF substrate. The increase in the CVD temperature during CNF preparation led to increased Raman intensity and EF value. The crystalline graphitic structure in CNFs consisting of π-bonds and intra-and inter-layer overlapping p-orbital possessed accumulated electron transfer, which remarkably yielded SERS enhancement. The present work opens potential future research avenues to use these magnetic CNFs as SERS substrate with a considerable EF in biosensor applications.

show abstract

Effect of NH3 gas ratio on the formation of nitrogen-doped carbon nanotubes using thermal chemical vapor deposition

Cited by 22 publications

References 26 publications

Wafer-Scale Fabrication of Nitrogen-Doped Reduced Graphene Oxide with Enhanced Quaternary-N for High-Performance Photodetection

Wafer-Scale Fabrication of Nitrogen-Doped Reduced Graphene Oxide with Enhanced Quaternary-N for High-Performance Photodetection

One-Step Chemical Vapor Deposition Synthesis of Hierarchical Ni and N Co-Doped Carbon Nanosheet/Nanotube Hybrids for Efficient Electrochemical CO₂ Reduction at Commercially Viable Current Densities

Magnetic Carbon Nanofibers Prepared with Ni and Ni/Graphitic Carbon Nanoparticle Catalysts for Glycine Detection Using Surface-Enhanced Raman Spectroscopy

Contact Info

Product

Resources

About

Effect of NH3 gas ratio on the formation of nitrogen-doped carbon nanotubes using thermal chemical vapor deposition

Cited by 22 publications

References 26 publications

Wafer-Scale Fabrication of Nitrogen-Doped Reduced Graphene Oxide with Enhanced Quaternary-N for High-Performance Photodetection

Wafer-Scale Fabrication of Nitrogen-Doped Reduced Graphene Oxide with Enhanced Quaternary-N for High-Performance Photodetection

One-Step Chemical Vapor Deposition Synthesis of Hierarchical Ni and N Co-Doped Carbon Nanosheet/Nanotube Hybrids for Efficient Electrochemical CO2 Reduction at Commercially Viable Current Densities

Magnetic Carbon Nanofibers Prepared with Ni and Ni/Graphitic Carbon Nanoparticle Catalysts for Glycine Detection Using Surface-Enhanced Raman Spectroscopy

Contact Info

Product

Resources

About

One-Step Chemical Vapor Deposition Synthesis of Hierarchical Ni and N Co-Doped Carbon Nanosheet/Nanotube Hybrids for Efficient Electrochemical CO₂ Reduction at Commercially Viable Current Densities