Preparation of WO3 nanorods with high specific surface area using double-walled carbon nanotubes as template

Rare Metals ◽  
2015 ◽  
Author(s):  
Yan-Hong Yin ◽  
Chun-An Ma ◽  
Zi-Ping Wu ◽  
Li-Tao Chen ◽  
You-Qun Chu
Keyword(s):  
Carbon Nanotubes ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The Influence of Fe/Al Molar Ratio on Microreactor-Based Catalyst Preparation and Carbon Nanotube Preparation

2021 ◽  
Vol 1036 ◽  
pp. 130-136
Author(s):  
Ting Qun Tan ◽  
Lei Geng ◽  
Yan Lin ◽  
Yan He
Keyword(s):  
Carbon Nanotubes ◽  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Small Diameter ◽  
High Specific Surface Area ◽  
Detection Methods ◽  
Molar Ratio ◽  
High Catalytic Activity

In order to prepare carbon nanotubes with high specific surface area, small diameter, low resistivity, high purity and high catalytic activity, the Fe-Mo/Al2O3 catalyst was prepared based on the microreactor. The influence of different Fe/Al molar ratios on the catalyst and the carbon nanotubes prepared was studied through BET, SEM, TEM and other detection methods. Studies have shown that the pore structure of the catalyst is dominated by slit pores at a lower Fe/Al molar ratio. The catalytic activity is the highest when the Fe/Al molar ratio is 1:1, reaching 74.1%. When the Fe/Al molar ratio is 1:2, the catalyst has a higher specific surface area, the maximum pore size is 8.63 nm, and the four-probe resistivity and ash content of the corresponding carbon nanotubes are the lowest. The higher the proportion of aluminum, the higher the specific surface area of the catalyst and the carbon nanotubes, and the finer the diameter of the carbon nanotubes, which gradually tends to relax. The results show that when the Fe/Al molar ratio is 1:2, although the catalytic activity of the catalyst is not the highest, the carbon nanotubes prepared have the best performance.

Frontiers of carbon materials as capacitive deionization electrodes

2020 ◽  
Vol 49 (16) ◽  
pp. 5006-5014 ◽  
Author(s):  
Yuanyuan Li ◽  
Nan Chen ◽  
Zengling Li ◽  
Huibo Shao ◽  
Liangti Qu
Keyword(s):  
Carbon Nanotubes ◽  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
High Specific Surface Area ◽  
Carbon Aerogels ◽  
Capacitive Deionization

Carbon materials are widely used as capacitive deionization (CDI) electrodes due to their high specific surface area (SSA), superior conductivity, and better stability, including activated carbon, carbon aerogels, carbon nanotubes and graphene.

CVD Synthesis of Multi-Walled Carbon Nanotubes onto Different Catalysts at Low Temperature

NANO ◽  
2018 ◽  
Vol 13 (04) ◽  
pp. 1850036 ◽  
Author(s):  
Guiqiang Diao ◽  
Hao Li ◽  
Hao Liang ◽  
Iryna Ivanenko ◽  
Tetiana Dontsova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Low Temperature ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Lithium Ion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs) were synthesized onto a series of individual and bimetallic catalysts by the chemical vapor deposition (CVD) of acetylene at low temperature (600[Formula: see text]C). The catalysts were prepared by two methods, i.e., precipitation and sol–gel, with two different carriers – MgO and Al2O3. The catalysts were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric (TG) analysis, low-temperature adsorption of nitrogen. The yield of the MWCNTs was calculated in two ways, while the highest yield of 800% was achieved onto the two-component NiO/Co2O3/MgO catalyst, SEM and transmission electron microscopy (TEM) results confirm that uniform tube-like structure MWCNTs with the yield of 410% were obtained onto Co2O3/Al2O3 catalyst. These MWCNTs are smooth and pointing in the same direction. Their tube diameter is about 20[Formula: see text]nm, which is the smallest around all observed MWCNTs. Moreover, nonuniform curved bamboo-like MWCNTs with nozzles in the yield of 760% were obtained onto NiO/V2O3/MgO catalyst. Their diameter ranges from 25[Formula: see text]nm to 50[Formula: see text]nm. Results show that single-component catalyst promotes the growth of uniform and smaller nanotubes. Among the as-grown nanotubes, their specific surface area increases and average pores diameter reduces after the treatment with concentrated nitric acid at reflux and washing condition. The largest specific surface area (305[Formula: see text]m2/g) and average pores diameter (26[Formula: see text]m2/g) are processed to MWCNTs grown onto the NiO/Co2O3/MgO catalyst. MWCNTs with such large structural adsorption characteristics and purity of more than 99% obtained with yield 800% show potential use for preparation of nanocomposites as anode materials in lithium ion batteries.

Macroscopic shaping of carbon nanotubes with high specific surface area and full accessibility

2012 ◽  
Vol 79 ◽  
pp. 128-131 ◽  
Author(s):  
Yuefeng Liu ◽  
Lam D. Nguyen ◽  
Tri Truong-Huu ◽  
Yu Liu ◽  
Thierry Romero ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area

Longitudinal unzipped carbon nanotubes with high specific surface area and trimodal pore structure

RSC Advances ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 8661-8668 ◽  
Author(s):  
Joah Han ◽  
Wonbin Kim ◽  
Hyun-Kyung Kim ◽  
Hee-Chang Youn ◽  
Joong Tark Han ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Activating Agent

This study reports unzipped carbon nanotubes (CNTs) with a trimodal (micro–meso–macro) pore structure using KOH as the activating agent.

Specific Surface Area of Carbon Fine Particles Including Single-Walled Carbon Nanotubes Synthesized by Hot-Filament Plasma Assisted Chemical Vapor Deposition

2014 ◽  
Vol 1586 ◽  
Author(s):  
Ryuhei Yamada ◽  
Yasuhiro Masaki ◽  
Yasuaki Hayashi
Keyword(s):  
Carbon Nanotubes ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Vapor Deposition ◽  
Fine Particles ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Hot Filament ◽  
Walled Carbon Nanotubes

ABSTRACTCarbon fine particles including single-walled carbon nanotubes (SWNTs) were synthesized by hot-filament and plasma assisted chemical vapor deposition. Specific surface area was evaluated for carbon fine particles synthesized under optimized conditions along with purified SWNTs and multi-walled carbon nanotubes (MWNTs) for comparison. The value of specific surface area for the synthesized carbon fine particles was smaller than the SWNTs, but larger than the MWNTs. Pore size distribution was analyzed with desorption isotherms by the DH method. Although smaller pores are included in the purified SWNTs than the synthesized carbon fine particles, pores of size larger than several nm were included more in the synthesized carbon fine particles.

Carbon Nanotube Anodes for Lithium Ion Batteries

2001 ◽  
Vol 706 ◽  
Author(s):  
Ryne P. Raffaelle ◽  
Thomas Gennett ◽  
Jeff Maranchi ◽  
Prashant Kumta ◽  
Aloysius F. Hepp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Specific Surface ◽  
Lithium Ion Batteries ◽  
Surface Area ◽  
Specific Surface Area ◽  
Anode Materials ◽  
Lithium Ion ◽  
Carbonaceous Materials ◽  
Walled Carbon Nanotubes

AbstractHighly purified single-wall carbon nanotubes (SWCNT) were investigated for use as an anode material for thin film lithium ion batteries. The high purity nanotubes were obtained through chemical refinement of soot generated by pulsed laser ablation. The purity of the nanotubes was determined via thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. The specific surface area and lithium capacity of the SWCNT's was compared to that of other conventional anode materials (i.e., carbon black, graphite, and multi-walled carbon nanotubes). The Brunauer, Emmett, and Teller (BET) technique based on nitrogen adsorption was used to measure the specific surface area of the various anode materials. The SWCNT's exhibited a specific surface area on the order of 915 m2/g, much higher than the other carbonaceous materials. Cyclic voltammetric behavior and the lithium-ion capacity of the materials were measured using a standard 3-electrode electrochemical cell. The cyclic voltammetry showed evidence of “staging” that was similar to other carbonaceous materials. The electrochemical discharge capacity of the purified single walled carbon nanotubes was in excess of 1300 mAh/g after 30 charge/discharge cycles when tested using a current density of 20μA/cm2.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

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