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Synthesis Of Carbon Nanotubes Over Supported Hybrid Catalyst Via Catalytic Chemical Vapor Deposition Of Acetylene
Download Synthesis Of Carbon Nanotubes Over Supported Hybrid Catalyst Via Catalytic Chemical Vapor Deposition Of Acetylene full books in PDF, epub, and Kindle. Read online Synthesis Of Carbon Nanotubes Over Supported Hybrid Catalyst Via Catalytic Chemical Vapor Deposition Of Acetylene ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Synthesis of Carbon Nanotubes Over Supported Hybrid Catalyst Via Catalytic Chemical Vapor Deposition of Acetylene by : Harnini Azira Abdullah
Download or read book Synthesis of Carbon Nanotubes Over Supported Hybrid Catalyst Via Catalytic Chemical Vapor Deposition of Acetylene written by Harnini Azira Abdullah and published by . This book was released on 2012 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Formulation of Hybrid Catalysts for the Synthesis of Carbon Nanotubes Using Gas-liquid Catalytic Chemical Vapor Deposition System by : Fatiha Ismail
Download or read book Formulation of Hybrid Catalysts for the Synthesis of Carbon Nanotubes Using Gas-liquid Catalytic Chemical Vapor Deposition System written by Fatiha Ismail and published by . This book was released on 2013 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Catalytic Chemical Vapor Deposition Synthesis of Carbon Nanotubes from Methane on SiO Supported Fe and Fe-Ni Catalysts by : Ayako Nakagawa
Download or read book Catalytic Chemical Vapor Deposition Synthesis of Carbon Nanotubes from Methane on SiO Supported Fe and Fe-Ni Catalysts written by Ayako Nakagawa and published by . This book was released on 2009 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Influences of operating conditions on the production of carbon nanotubes (CNTs) were studied using Fe and Fe-Ni bimetallic catalysts supported on silicon monoxide (SiO). The catalysts were prepared in three steps: (1) impregnation of SiO powders with ferric nitride or combinations of ferric and nickel nitrides, (2) oxidation of nitrides in an air stream, and (3) grinding the powders obtained. CNTs were successfully synthesized by catalytic CVD using NH3/CH4 mixtures in a horizontal tubular flow reactor. The following process parameters were varied to investigate their effects on the growth rates of CNTs. The morphologies of catalysts and product CNTs were observed by scanning electron microscope (SEM). The particle size of SiO, metal composition, metal loading, temperature for catalyst oxidation, extent of grinding of catalysts, NH3 pretreatment time, reaction temperature for CNT growth, reaction time, and NH3/CH4 feed ratio. Two different average sizes of SiO particles, 8 [mu]m and 44 [mu]m, were compared based on the growth of CNTs in 5 min. Catalysts supported on 44 [mu]m average sized SiO particles demonstrated higher yields when they were not pretreated in an NH3 stream. When 1 wt% Fe was loaded, aligned CNTs were formed, and a highest growth rate per unit mass of catalyst was observed. The range of oxidation temperature to achieve highest catalyst activities depended on metals and metal contents: 600 - 750°C for 1 wt% Fe, 450 - 600°C for 3 wt% Fe, and 750 - 900°C for Fe-Ni. Grinding catalysts for at least 3 minutes increased the growth rate of CNTs by approximately 40 percent. The growth of CNTs was enhanced when no NH3 pretreatment of catalysts was carried out, regardless of metals and metal contents. However, CNTs did not grow appreciably from methane without ammonia. An NH3/CH4 feed ratio of 0.15 - 0.25 was observed to yield highest growth rates. The reaction temperature to achieve highest CNT growth rates was found to be in the range between 990 and 1000 °C. The growth of CNTs was not linear but decreased with reaction time.
Book Synopsis PRODUCTION OF CARBON NANOTUBES BY CHEMICAL VAPOR DEPOSITION. by :
Download or read book PRODUCTION OF CARBON NANOTUBES BY CHEMICAL VAPOR DEPOSITION. written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT PRODUCTION OF CARBON NANOTUBES BY CHEMICAL VAPOR DEPOSITION Ayhan, Umut Barýþ M.S., Department of Chemical Engineering Supervisor: Prof. Dr. Güngör Gündüz Co-Supervisor: Assoc. Prof. Dr. Burhanettin Çiçek July 2004, 75 pages Carbon nanotubes, which is one of the most attractive research subject for scientists, was synthesized by two different methods: Chemical vapor deposition (CVD), a known method for nanotube growth, and electron beam (e-beam), a new method which was used for the first time for the catalytic growth of carbon nanotubes. In both of the methods, iron catalyst coated silica substrates were used for the carbon nanotube growth, that were prepared by the Sol-Gel technique using aqueous solution of Iron (III) nitrate and tetraethoxysilane. The catalytic substrates were then calcined at 450 °C under vacuum and iron was reduced at 500°C under a flow of nitrogen and hydrogen. In CVD method the decomposition of acetylene gas was achieved at 600 °C and 750 °C and the carbon was deposited on the iron catalysts for nanotube growth. However, in e-beam method the decomposition of acetylene was achieved by applying pulsed high voltage on the gas and the carbon deposition on the silica substrate were done. The samples from both of the methods were characterized using transmission electron microscopy (TEM) and Raman spectroscopy techniques. TEM images and Raman spectra of the samples show that carbon nanotube growth has been achieved in both of the method. In TEM characterization, all nanotubes were found to be multi-walled carbon nanotubes (MWNT) and no single-walled carbon nanotubes (SWNT) were pictured. However, the Raman spectra show that there are also SWNTs in some of the samples.
Book Synopsis Synthesis and Characterisation of Multi-walled Carbon Nanotubes on Supported Catalysts Via Catalytic Chemical Vapour Deposition by : Jia Chee Tee
Download or read book Synthesis and Characterisation of Multi-walled Carbon Nanotubes on Supported Catalysts Via Catalytic Chemical Vapour Deposition written by Jia Chee Tee and published by . This book was released on 2006 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Perspective of Carbon Nanotubes by : Hosam El-Din Saleh
Download or read book Perspective of Carbon Nanotubes written by Hosam El-Din Saleh and published by BoD – Books on Demand. This book was released on 2019-12-11 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon nanotubes belong to new nanomaterials and have been known for almost 20 years, but their history is somewhat lengthier. They have been identified as promising candidates for various applications.High-temperature preparation techniques are conventional techniques for the synthesis of carbon nanotubes using arc discharge or laser ablation, but today these methods are being replaced by low-temperature vapor deposition techniques, since orientation, alignment, nanotube length, diameter, purity, and density of carbon nanotubes can be precisely controlled. The synthesis of carbon nanotubes by chemical vapor deposition on catalyst arrays leads to nanotube models grown from specific sites on surfaces. The controlled synthesis of nanotubes opens up interesting possibilities in nanoscience and nanotechnologies, including electrical, mechanical and electromechanical properties and devices, chemical functionalization, surface chemistry and photochemistry, molecular sensors, and interfacing with moderate biological systems.Carbon nanotubes are used in many applications due to their unique electrical, mechanical, optical, thermal, and other properties. Conductive and high-strength composite materials, energy saving and energy conversion devices, sensors, visualization of field emissions and sources of radiation, means for storing hydrogen, and nanoscale semiconductor devices, probes, and interconnections are some of the many applications of carbon nanotubes.
Book Synopsis Nanohybrid Catalyst based on Carbon Nanotube by : Rasel Das
Download or read book Nanohybrid Catalyst based on Carbon Nanotube written by Rasel Das and published by Springer. This book was released on 2017-05-23 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces carbon nanotubes as a matrix for efficient nanohybrid catalysis. The preparation and use of such materials in ultra-grade water purification is described. Simple chemical methods for purification and functionalization of carbon nanotubes prior to their use is also detailed. The author also discusses the potential use of nanotube-based nanobiohybrid catalysts in the removal of organic pollutants.
Book Synopsis Synthesis of Carbon Nanotubes by Catalytic Chemical Vapor Deposition by : GuiPing Dai
Download or read book Synthesis of Carbon Nanotubes by Catalytic Chemical Vapor Deposition written by GuiPing Dai and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a new carbon material in the twenty-first century, carbon nanotubes (CNTs) have excellent optical, electrical, magnetic, thermal, chemical, and mechanical properties. There are many synthesis methods to produce CNTs. Compared with other methods, chemical vapor deposition (CVD) is the most effective method that has broad prospects for large-scale control of CNTs in recent years due to its simple equipment, simple operation, and lower cost. In order to gain a comprehensive understanding of the controlling parameters about the formation of CNTs, this chapter reviews the latest progress in the preparation of CNTs by CVD from three of the most important influencing factors: carbon sources, catalysts, and substrates. Among them, the catalyst is the most influential factor for the morphology, structure, and properties of CNTs. It should be pointed out that many growth factors can control the particle size distribution, composition, and structure of the catalysts, such as catalyst substrate, metal transition components added, calcination temperature, etc.
Book Synopsis Carbon Nanotubes by : Ajay Kumar Mishra
Download or read book Carbon Nanotubes written by Ajay Kumar Mishra and published by Nova Science Publishers. This book was released on 2012-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon nanotubes possess unusual fascinating properties which have attracted the scientific world. This book covers a very wide domain of research and development where the synthesis and properties of carbon nanotubes are discussed. This book describes the carbon nanotube general introduction, various synthesis procedures and properties. This book is going to be beneficial to the researchers who are working for their postgraduate degree in nanomaterials and nanotechnology. This book also provides a platform for all the academics and researchers as it covers a vast background for the recent literature, abbreviations, and summaries. This book will be worth reading for the researchers who are more interested in the general overview of carbon nanotubes, fundamentals concepts and various synthetic procedures in the multidisciplinary areas. This book contains the fundamental knowledge with the recent advancements for the research and development in the field of nanomaterials and nanotechnology.
Book Synopsis Investigation Into the Growth Mechanisms of Carbon Nanotubes Formed Using Thermal Chemical Vapour Deposition by : William Murray Whyte
Download or read book Investigation Into the Growth Mechanisms of Carbon Nanotubes Formed Using Thermal Chemical Vapour Deposition written by William Murray Whyte and published by . This book was released on 2011 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Substrate and Catalyst Design for Chemical Vapor Deposition Synthesis of Carbon Nanotubes on Si, Cu and SiC by : Ge Li
Download or read book Substrate and Catalyst Design for Chemical Vapor Deposition Synthesis of Carbon Nanotubes on Si, Cu and SiC written by Ge Li and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis discussed the design of substrate and catalyst for chemical vapor deposition synthesis of carbon nanotubes (CNT). It was focused on synthesis CNTs on the various substrates, such as Si, Cu and SiC. The research was structured as following: (1) characterization of the Al2O3 buffer layer produced by plasma oxidation in order to find out the its effect on CNT growth; (2) study of the position parameters in CVD system to optimize process condition for manufacturing CNTs; (3) exploring novel composite catalyst alloys; (4) design new substrate for synthesis of vertically aligned CNTs on Cu and SiC for thermal application. Advanced surface analysis techniques were used to explore the role of AI2O3 supporting layer and of the composite catalyst. Although the data is insufficient for coming to a conclusion on the mechanism behind CNT super-growth, the preliminary studies provide guidance for selecting catalyst composite which will allow scaling up CNT production. A series of experiments using two CVD system (ET 1000 & ET 3000) were conducted which allowed for optimize the growth parameter and produce CNT arrays with uniform length. Vertically aligned CNTs arrays were successfully synthesized on copper and SiC substrates by adding supporting layers and adjusting the CVD growth conditions. This achievement engenders a wide range of future application in the field of thermal management.
Book Synopsis Synthesis, Technology and Applications of Carbon Nanomaterials by : Suraya Abdul Rashid
Download or read book Synthesis, Technology and Applications of Carbon Nanomaterials written by Suraya Abdul Rashid and published by Elsevier. This book was released on 2018-10-10 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis, Technology and Applications of Carbon Nanomaterials explores the chemical properties of different classes of carbon nanomaterials and their major applications. As carbon nanomaterials are used for a variety of applications due to their versatile properties and characteristics, this book discusses recent advances in synthesis methods, characterization, and applications of 0D -3D dimensional carbon nanomaterials. It is an essential resource for readers focusing on carbon nanomaterials research. Explores the chemical properties of different classes of carbon nanomaterials and their major applications Discusses recent advances in synthesis methods, characterization, and applications of 0D -3D dimensional carbon nanomaterials
Book Synopsis Scalable Carbon Nanotube Growth and Design of Efficient Catalysts for Fischer-Tropsch Synthesis by : Haider H. Almkhelfe
Download or read book Scalable Carbon Nanotube Growth and Design of Efficient Catalysts for Fischer-Tropsch Synthesis written by Haider H. Almkhelfe and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The continued depletion of fossil fuels and concomitant increase in greenhouse gases have encouraged worldwide research on alternative processes to produce clean fuel. Fischer-Tropsch synthesis (FTS) is a heterogeneous catalytic reaction that converts syngas (CO and H2) to liquid hydrocarbons. FTS is a well-established route for producing clean liquid fuels. However, the broad product distribution and limited catalytic activity are restricting the development of FTS. The strong interactions between the active metal catalyst (Fe or Co) and support (Al2O3, SiO2 and TiO2) during post-synthesis treatments of the catalyst (such as calcination at ~500°C and reduction ~550°C) lead to formation of inactive and unreducible inert material like Fe2SiO4, CoAl2O4, Co2SiO4. The activity of FTS catalyst is negatively impacted by the presence of these inactive compounds. In our study, we demonstrate the use of a modified photo-Fenton process for the preparation of carbon nanotube (CNT)-supported Co and Fe catalysts that are characterized by small and well-dispersed catalyst particles on CNTs that require no further treatments. The process is facile, highly scalable, and involves the use of green catalyst precursors and an oxidant. The reaction kinetic results show high CO conversion (85%), selectivity for liquid hydrocarbons and stability. Further, a gaseous product mixture from FTS (C1-C4) was utilized as an efficient feedstock for the growth of high-quality, well-aligned single-wall carbon nanotube (SWCNT) carpets of millimeter-scale heights on Fe and (sub) millimeter-scale heights on Co catalysts via chemical vapor deposition (CVD). Although SWCNT carpets were grown over a wide temperature range (between 650 and 850°C), growth conducted at optimal temperatures for Co (850°C) and Fe (750°C) yielded predominantly SWCNTs that are straight, clean, and with sidewalls that are largely free of amorphous carbon. Also, low-temperature CVD growth of CNT carpets from Fe and Fe-Cu catalysts using a gaseous product mixture from FTS as a superior carbon feedstock is demonstrated. The efficiency of the growth process is evidenced by the highly dense, vertically aligned CNT structures from both Fe and Fe-Cu catalysts even at temperatures as low as 400°C-a record low growth temperature for CNT carpets obtained via conventional thermal CVD. The use of FTS-GP facilitates low-temperature growth of CNT carpets on traditional (alumina film) and nontraditional substrates (aluminum foil) and has the potential of enhancing CNT quality, catalyst lifetime, and scalability. We demonstrate growth of SWCNT carpets with diameter distributions that are smaller than SWCNTs in conventional carpets using a CVD process that utilizes the product gaseous mixture from Fischer-Tropsch synthesis (FTS-GP). The high-resolution transmission electron microscopic (HR-TEM) and Raman spectroscopic results reveal that the use of a high melting point metal as a catalyst promoter in combination with either Co (1.5 nm ± 0.7) at 850oC or Fe (1.9 nm ± 0.8) at 750oC yields smaller-diameter SWCNT arrays with narrow diameter distributions. Scalable synthesis of carbon nanotubes (CNTs), carbon nanofibers (CNFs), and onion like carbon (OLC) in a batch reactor using supercritical fluids as a reaction media is demonstrated. The process utilizes toluene, ethanol, or butanol as a carbon precursor in combination with ferrocene that serves as a catalyst precursor and a secondary carbon source. The use of supercritical fluids for growth does not only provide a route for selective growth of a variety of carbon nanomaterials, but also provides a unique one-step approach that is free of aggressive acid treatment for synthesis of CNT-supported metallic nanoparticle composites for catalysis and energy storage applications.
Book Synopsis Hybrid Nanomaterials by : Rafael Vargas-Bernal
Download or read book Hybrid Nanomaterials written by Rafael Vargas-Bernal and published by BoD – Books on Demand. This book was released on 2020-06-10 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two of the hottest research topics today are hybrid nanomaterials and flexible electronics. As such, this book covers both topics with chapters written by experts from across the globe. Chapters address hybrid nanomaterials, electronic transport in black phosphorus, three-dimensional nanocarbon hybrids, hybrid ion exchangers, pressure-sensitive adhesives for flexible electronics, simulation and modeling of transistors, smart manufacturing technologies, and inorganic semiconductors.
Book Synopsis Effects of Molar Ratio of Iron Catalyst on Synthesis of Carbon Nanotubes Via Catalytic Chemical Vapor Deposition by : Setareh Monshi Toussi
Download or read book Effects of Molar Ratio of Iron Catalyst on Synthesis of Carbon Nanotubes Via Catalytic Chemical Vapor Deposition written by Setareh Monshi Toussi and published by . This book was released on 2010 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Carbon Nanotubes by : Stephan Parker Turano
Download or read book Carbon Nanotubes written by Stephan Parker Turano and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon nanotubes (CNTs) have become a popular area of materials science research due to their outstanding material properties coupled with their small size. CNTs are expected to be included in a wide variety of applications and devices in the near future. Among these devices which are nearing mass production are electrochemical double layer (ECDL) supercapacitors. The current methods to produce CNTs are numerous, with each synthesis variable resulting in changes in the physical properties of the CNT. A wide array of studies have focused on the effects of specific synthesis conditions. This research expands on earlier work done using bulk nickel catalyst, alumina supported iron catalyst, and standard chemical vapor deposition (CVD) synthesis methods. This work also investigates the effect of an applied voltage to the CVD chamber during synthesis on the physical nature of the CNTs produced. In addition, the work analyzes a novel nickel catalyst system, and the CNTs produced using this catalyst. The results of the effects of synthesis conditions on resultant CNTs are included. Additionally, CNT based ECDL supercapacitors were manufactured and tested. Scanning electron microscope (SEM) analysis reveals that catalyst choice, catalyst thickness, synthesis temperature, and applied voltage have different results on CNT dimensions. Nanotube diameter distribution and average diameter data demonstrate the effect of each synthesis condition. Additionally, the concept of an alignment parameter is introduced in order to quantify the effect of an electric field on CNT alignment. CNT based ECDL supercapacitors testing reveals that CNTs work well as an active material when a higher purity is achieved. The molarity of the electrolyte also has an effect on the performance of CNT based ECDL supercapacitors. On the basis of this research, we conclude that CNT physical dimensions can be moderately controlled based on the choice of synthesis conditions. Also, the novel nickel catalyst system investigated in this research has potential to produce bulk quantities of CNT under specific conditions. Finally, purified CNTs are recommended as a suitable active material for ECDL supercapacitors.
Book Synopsis Evolution of Metal Catalyst During CVD Synthesis of Carbon Nanotubes by :
Download or read book Evolution of Metal Catalyst During CVD Synthesis of Carbon Nanotubes written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The revolutionary discovery of carbon nanotubes (CNT) in 1991 led to intense research activities in the domain of carbon science. The fascinating properties of these unique material has opened a great number of potential applications e.g. as electron field emitters, one-dimensional conductors, supercapacitors, reinforcing fibres or hydrogen storage. Despite these stunning technical progresses there is still much struggle in the development of a synthesis method suitable for commercial applications. A leading candidate is the chemical vapour deposition (CVD) technique. Nucleation and growth of CNTs are induced by the decomposition of carbon-containing gases (CO, CO2, C2H2, etc) over a metallic catalyst at temperatures between 600°C and 1200°. CVD is a widely used technique to generate CNTs in large quantities and much progress has been made from the point of view of the yield, the synthesis costs or the purity of the products. But the great conundrum of CVD process remains the growth mechanism. A key reaction step for nanotube growth seems to be diffusion of carbon through the metal catalyst and the most active metals are iron, cobalt and nickel but their catalytic action depends on the type of precursor, the type of substrate and of the reactive gases used. Highly controversial is the actual chemical nature of the active catalyst e.g. if it is present as metal, carbide or as mixed phase. So far few investigations of the chemical and morphological evolution of the catalyst during CVD process have been performed. This thesis focuses on the evolution of nickel-, cobalt-, chromium- and molybdenum-based catalysts under a nitrogen/acetylene and a nitrogen/acetylene/ hydrogen atmosphere at 600°C and 750°C. In order to elucidate the nature of the catalyst during synthesis runs an X-ray diffractometer equipped with a heating stage and an atmosphere controlling system was used to study in-situ the evolution of metal nitrate films. Samples quenched after different pyrolysis ti.
