scholarly journals Characterization of Carbon Nanofibers Treated with Thermal Nitrogen as a Catalyst Support Using Point-of-Zero Charge Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Thien Duc Nguyen Van ◽  
Suriati Sufian ◽  
Nurlidia Mansor ◽  
Noorhana Yahya
Keyword(s):  
Carbon Nanofibers ◽  
Amorphous Carbon ◽  
Active Sites ◽  
Gas Flow ◽  
Carbon Nanofiber ◽  
Catalyst Support ◽  
Carbon Surface ◽  
Point Of Zero Charge ◽  
Zero Charge ◽  
Defect Sites

The chemical and physical purification of carbon nanofiber exposes more anchoring sites between meal precursors and carbon surface but thermal N2gas flow maintains the crystal’s structure as well as its defect and edge sites, referred to as active sites or anchoring sites. After calcination in nitrogen at 450°C, samples were characterized by Raman spectra X-ray diffraction, as well as thermogravimetric and nitrogen physisorption analyses. Results showed a relatively lower fraction of amorphous carbon to graphite, indicating a greater removal of amorphous carbon. Moreover, the disorder intensity of carbon nanofibers that were treated in N2flow rate of 1 L/min and 3 hours, called 1Gcom-3h sample, achieved far more defect sites compared with unmodified carbon nanofiber. In addition, the surface areas of mesoporous carbon nanofibers decreased over prolonged residence time. The carbon nanofiber support-metal cation interaction therefore improved the deposition of iron when the point-of-zero charge reading was greater than four.

Use of Graphite Nanofibers as a Novel Catalyst Support Medium for Hydrogenation Reactions

1996 ◽  
Vol 454 ◽  
Author(s):  
C. Park ◽  
N. M. Rodriguez ◽  
R. T. K. Baker
Keyword(s):  
Carbon Nanofibers ◽  
Carbon Nanofiber ◽  
Catalyst Support ◽  
Catalytic Behavior ◽  
Graphite Nanofibers ◽  
Nickel Particles ◽  
Support Medium ◽  
Different Types ◽  
Hydrogenation Reactions ◽  
Novel Catalyst

ABSTRACTIn this investigation we elected to use the hydrogenation of 1-butene as probe reactions in an attempt to monitor any possible changes in catalytic behavior resulting from supporting 5 wt.% nickel on different types of carbon nanofibers compared to the performance of the same metal loading on more traditional carriers, including γ-Al2O3 and active carbon. In all cases the carbon nanofiber supported nickel particles are found to exhibit superior activity and significant changes in selectivity to that found from the same metal supported on traditional carriers.

Vertically Aligned Carbon Nanofiber based Biosensor Platform for Glucose Sensor

2014 ◽  
Vol 23 (01n02) ◽  
pp. 1450006 ◽  
Author(s):  
Khandaker A. Al Mamun ◽  
Fahmida S. Tulip ◽  
Kimberly MacArthur ◽  
Nicole McFarlane ◽  
Syed K. Islam ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Glucose Sensor ◽  
Dynamic Range ◽  
Carbon Nanofiber ◽  
Silicon Substrates ◽  
Forest Density ◽  
Defect Sites ◽  
Vertically Aligned ◽  
Biosensor Applications ◽  
Made In

Vertically aligned carbon nanofibers (VACNFs) have recently become an important tool for biosensor design. Carbon nanofibers (CNF) have excellent conductive and structural properties with many irregularities and defect sites in addition to exposed carboxyl groups throughout their surfaces. These properties allow a better immobilization matrix compared to carbon nanotubes and offer better resolution when compared with the FET-based biosensors. VACNFs can be deterministically grown on silicon substrates allowing optimization of the structures for various biosensor applications. Two VACNF electrode architectures have been employed in this study and a comparison of their performances has been made in terms of sensitivity, sensing limitations, dynamic range, and response time. The usage of VACNF platform as a glucose sensor has been verified in this study by selecting an optimum architecture based on the VACNF forest density.

scholarly journals Modification of the surface chemistry of activated carbon and its influence on methylene blue adsorption

2018 ◽  
Vol 5 (1) ◽  
pp. 374
Author(s):  
David Wibowo ◽  
Lanny Setyadhi ◽  
Suryadi Ismadji
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Surface Chemistry ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Carbon Surface ◽  
Point Of Zero Charge ◽  
Titration Method ◽  
Zero Charge ◽  
Boehm Titration

The adsorption behavior of activated carbons is determined not only by their porous structures but also by the chemical nature of its surface. The surface chemistry of activated carbons can be selectively modified in order to improve their adsorption capacity. In this study, a NORIT granular activated carbon was treated by oxidant (HNO3) and non-oxidant acid (HCI) at different concentrations and temperatures. The surface chemistries of the materials were characterized by Boehm titration method and by the determination of the point of zero charge (pHPZC).The adsorption properties of the selected samples were studied by adsorption of methylene blue, which is one of the important dyes and found in many textile effluents. In addition, the pore structures of the modified carbons were also studied by argon adsorption at 87.29 K. As results, it was observed that both HN03 and HCI treatments could increase the surface acidity of activated carbons. Activated carbons modified by HCI gave the best performance on the adsorption of methylene blue.Keywords: Activated Carbon, Surface Chemistry, Chemical Treatment, Boehm Titration Method, Adsorption AbstrakKemampuan adsorpsi karbon akti.ftidak hanya ditentukan oleh struktur pori tetapijuga dipengaruhi oleh sifat kimia dari permukaannya. Sifat kimia permukaan karbon aktif dapat secara selektif dimodifikasi dengan tujuan untuk lebih meningkatkan kapasitas adsorpsinya. Pada penelitian ini, karbon aktif NORIT granular ditreatment dengan menggunakan asam oksidator (HNO) dan non-oksidator (HCI) pada berbagai konsentrasi dan suhu. Sifat kimia permukaan karbon aktif dikarakterisasi dengan menggunakan metode titrasi Boehm serta dengan penentuan point of zero charge (pHPZC). Kemampuan adsorpsinya diuji dengan mengadsorp larutan methylene blue, dimana methylene blue merupakan salah satu komponen dalam limbah tekstil. Sedangkan struktur pori karbon aktif dianalisa dengan adsorpsi Ar pada suhu 87,29 K. Penelitian ini menunjukkan bahwa baik treatment dengan HNO3 maupun HCI dapat mengakibatkan terjadinya peningkatan sifat asam pada permukaan karbon aktif. Karbon aktif yang diberi perlalatan dengan HCI memberikan kemampuan adsorpsi yang paling baik dalam adsorpsi larutan methylen biru.Kata Kunci: Karbon Aktif, Sifat Kimia Permukaan, Perlakuan dengan Larutan Kimia, Metode Titrasi Boehm, Adsorpsi

Hydrogen Production by Catalytic Decomposition of Methane over Carbon Nanofibers

2006 ◽  
Vol 510-511 ◽  
pp. 30-33 ◽  
Author(s):  
Ling Han ◽  
Tae Ki Lim ◽  
Young Jun Kim ◽  
Hyun Sik Hahm ◽  
Myung Soo Kim
Keyword(s):  
Hydrogen Production ◽  
Carbon Black ◽  
Carbon Nanofibers ◽  
Active Sites ◽  
Carbon Nanofiber ◽  
Flow Reactor ◽  
Catalytic Decomposition ◽  
Methane Decomposition ◽  
Decomposition Of Methane ◽  
Carbon Catalysts

Catalytic decomposition of methane is an environmentally attractive approach to CO2-free hydrogen production. The decomposition of methane over carbon nanofibers was carried out in a fixed bed flow reactor. The objectives of this study are to demonstrate the activity of carbon nanofibers for methane decomposition in comparison with that of carbon black and to investigate the nature of active sites in the carbon catalysts. The catalytic activities of different carbon catalysts were found in the following order: carbon nanofiber > HI-900L carbon black > N330 carbon black > non-catalyst. After investigating the surface area and mass of the carbon catalysts after methane decomposition, the nature of active sites was discused.

Cytocompatibility of Carbon Nanofiber Materials for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Carbon Fiber ◽  
Surface Energy ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
Carbon Nanofiber ◽  
Fiber Composite ◽  
Scar Tissue ◽  
Pc 12 Cells ◽  
Low Surface Energy ◽  
Poly Carbonate

AbstractSince the cytocompatibility of carbon nanofibers with respect to neural applications remains largely uninvestigated, the objective of the present in vitro study was to determine cytocompatibility properties of formulations containing carbon nanofibers. Carbon fiber substrates were prepared from four different types of carbon fibers, two with nanoscale diameters (nanophase, or less than or equal to 100 nm) and two with conventional diameters (or greater than 200 nm). Within these two categories, both a high and a low surface energy fiber were investigated and tested. Astrocytes (glial scar tissue-forming cells) and pheochromocytoma cells (PC-12; neuronal-like cells) were seeded separately onto the substrates. Results provided the first evidence that astrocytes preferentially adhered on the carbon fiber that had the largest diameter and the lowest surface energy. PC-12 cells exhibited the most neurites on the carbon fiber with nanodimensions and low surface energy. These results may indicate that PC-12 cells prefer nanoscale carbon fibers while astrocytes prefer conventional scale fibers. A composite was formed from poly-carbonate urethane and the 60 nm carbon fiber. Composite substrates were thus formed using different weight percentages of this fiber in the polymer matrix. Increased astrocyte adherence and PC-12 neurite density corresponded to decreasing amounts of the carbon nanofibers in the poly-carbonate urethane matrices. Controlling carbon fiber diameter may be an approach for increasing implant contact with neurons and decreasing scar tissue formation.

Cytocompatibility and Material Properties of Poly-carbonate Urethane/Carbon Nanofiber Composites for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Material Properties ◽  
Carbon Nanofiber ◽  
Scar Tissue ◽  
Tissue Response ◽  
Positive Interactions ◽  
Weight Percentage ◽  
Poly Carbonate

AbstractCarbon nanofibers possess excellent conductivity properties, which may be beneficial in the design of more effective neural prostheses, however, limited evidence on their cytocompatibility properties exists. The objective of the present in vitro study was to determine cytocompatibility and material properties of formulations containing carbon nanofibers to predict the gliotic scar tissue response. Poly-carbonate urethane was combined with carbon nanofibers in varying weight percentages to provide a supportive matrix with beneficial bulk electrical and mechanical properties. The substrates were tested for mechanical properties and conductivity. Astrocytes (glial scar tissue-forming cells) were seeded onto the substrates for adhesion. Results provided the first evidence that astrocytes preferentially adhered to the composite material that contained the lowest weight percentage of carbon nanofibers. Positive interactions with neurons, and, at the same time, limited astrocyte functions leading to decreased gliotic scar tissue formation are essential for increased neuronal implant efficacy.

scholarly journals A flexible and highly sensitive pressure sensor based on three-dimensional electrospun carbon nanofibers

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 13898-13905
Author(s):  
Chuan Cai ◽  
He Gong ◽  
Weiping Li ◽  
Feng Gao ◽  
Qiushi Jiang ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Pressure Sensor ◽  
Carbon Nanofiber ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Highly Sensitive ◽  
Sensitive Pressure

A three-dimensional electrospun carbon nanofiber network was used to measure press strains with high sensitivity.

Co3Fe7 nanoparticles encapsulated in porous nitrogen-doped carbon nanofiber as bifunctional electrocatalysts for rechargeable zinc-air battery

2021 ◽  
Author(s):  
Miaomiao Liu ◽  
Yulong He ◽  
Jintao Zhang
Keyword(s):  
Oxygen Reduction ◽  
Active Sites ◽  
Carbon Nanofiber ◽  
Nitrogen Doped ◽  
Bifunctional Electrocatalysts ◽  
Air Battery ◽  
Nitrogen Doped Carbon ◽  
Carbon Based

Exploration of inexpensitive and high perfomance carbon-based electrocatalyst with abundant active sites for oxygen reduction and evolution reactions is vital for enhancing the performance of zinc air battery. Herein, the...

scholarly journals Phase-selective active sites on ordered/disordered titanium dioxide enable exceptional photocatalytic ammonia synthesis

2021 ◽  
Author(s):  
Jinsun Lee ◽  
Xinghui Liu ◽  
Ashwani Kumar ◽  
Yosep Hwang ◽  
Eunji Lee ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Active Sites ◽  
Rational Design ◽  
Ammonia Synthesis ◽  
Reduction Reaction ◽  
Band Structures ◽  
Electronic Band ◽  
Defect Sites ◽  
Electronic Band Structures ◽  
Reaction Routes

This work highlights the importance of a rational design for more energetically suitable nitrogen reduction reaction routes and mechanisms by regulating the electronic band structures with phase-selective defect sites.

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