M. S. Shamsudin

Effect of Synthesis Temperature on the Growth Iron-Filled Carbon Nanotubes as Evidenced by Structural, Micro-Raman, and Thermogravimetric Analyses

Tubular structure and well dense of aligned carbon nanotubes (CNTs) were formulated using two-stage catalytic chemical vapor deposition apparatus. In this experiment, aligned CNT was synthesized in the range of 700–900°C temperatures with increment rate of 50°C per sample. The aligned CNT properties were investigated via field emission scanning electron microscope, micro-Raman spectrometer and thermogravimetric analyzer. The experimental results showed that aligned CNT properties were highly dependent on synthesis temperature changes. The optimum temperature of higher crystallinity was observed at 800°C synthesis temperature. However, the highest yield of nanotubes (~99.99%) was obtained at 900°C synthesis temperature. Aligned CNT orientation was in a parallel form and packed together in orderly manner. The behaviors of aligned CNT will be discussed in detail in this paper.

Impact of Thermal Annealing under Nitrogen Ambient on Structural, Micro-Raman, and Thermogravimetric Analyses of Camphoric-CNT

A systematical study of the effects on thermal annealing treatment under nitrogen ambient on the structural, micro-Raman, and thermogravimetric analyses of camphoric-carbon nanotubes (CNT) has been undertaken. Heat treatment of camphoric-CNT under nitrogen ambient was found to be an efficient technique of removing noncrystalline carbon and residual transition metal. Based on structural analysis, the heat-treated samples showed a clear view of overall camphoric-CNT structure.

Effect of iron and cobalt catalysts on the growth of carbon nanotubes from palm oil precursor

Catalysts which are typically a transition metal is mandatory and plays an important role in the production of CNT. In this work, the effect of iron (Fe) and cobalt (Co) nitrate catalyst on the growth of carbon nanotubes (CNT) were systematically studied. Green bio-hydrocarbon precursor namely palm oil was used as a precursor. The synthesis was done using thermal chemical vapour deposition method at temperature of 750°C for 15 min synthesis time. The Fe and Co solution were spin-coated separately on silicon substrate at speed of 3000 rev.min-1. The CNT characteristics were analyzed using field emission scanning electron microscopy and micro-Raman spectroscopy. The experimental results revealed that CNT properties were strongly affected by the catalyst type. CNT catalyzed by Co yields large diameter, crooked tube and lower quality, whereas CNT produced by Fe catalyst results in the smallest diameter and reasonably good graphitization. As a conclusion, Fe was considered as the optimum catalyst for better CNT structure and crystallinity. This was due to efficient, uniform and stable Fe catalytic activity as compared to Co catalyst in producing CNT.

An investigation on the formation of carbon nanotubes by two-stage chemical vapor deposition

High density of carbon nanotubes (CNTs) has been synthesized from agricultural hydrocarbon: camphor oil using a one-hour synthesis time and a titanium dioxide sol gel catalyst. The pyrolysis temperature is studied in the range of 700-900°C at increments of 50°C. The synthesis process is done using a custom-made two-stage catalytic chemical vapor deposition apparatus. The CNT characteristics are investigated by field emission scanning electron microscopy and micro-Raman spectroscopy. The experimental results showed that structural properties of CNT are highly dependent on pyrolysis temperature changes.

Structural and thermal behaviors of iron-filled align carbon nanotubes formulated by two-stage catalytic chemical vapor deposition

Finding on the one-dimensional purified aligned carbon nanotubes (ACNT) was prepared using botanical hydrocarbon: camphor powder in a two-stage catalytic chemical vapor deposition will be presented. For the first time, the hydrocarbon source and catalyst were patterned in different alumina boats in the system. The growth of ACNT has achieved free standing formation with higher aspect ratio. In contrast, unpurified carbon nanotubes have some drawbacks and require some treatments to fully utilize their capabilities in various applications. The results reveal that the crystallinity and purity of functionalized align carbon nanotubes was increased after wet-chemical technique and heat treatment process. In this paper, the results provide evidence showing that it was in good agreement with the field emission scanning electron microscopy, micro-Raman and thermogravimetric analysis.

BET Analysis on Carbon Nanotubes: Comparison between Single and Double Stage Thermal CVD Method

Carbon nanotubes have many applications and therefore widely produced. However, it is limited due to the high production cost. In this paper, by preparing the CNTs using the Thermal Chemical Vapor Deposition method, CNTs were synthesized with a low cost method since palm oil is used as the precursor which is a biodegradable and cheap source. The aerosol or spray pyrolysis method is used for single stage and double stage TCVD method. Then, the samples were both collected at deposition temperature of 750°C and were characterized using Brunauer, Emmett and Teller (BET) method. Since CNTs are said to have high surface area therefore BET method is used to prove this fact. Results showed that by using double stage TCVD method, more CNTs were synthesized compared to single stage TCVD method which produced more impurities namely amorphous carbon. CNTs also have higher surface area compared to amorphous carbon. To support this result, the images of the CNTs produced by same method but different parameters were characterized with field emission scanning electron microscope (FE-SEM) and the raman spectra was determined by the raman spectroscopy characterization.

Novel Method: Coral Like Structure of Align Carbon Nanotubes (A-CNTs) on Porous Silicon Template (PSiT) without Catalyst; Green Approach

Align Carbon Nanotubes (A-CNTs) is very promising materials and offer attractive applications especially in opto-emission devices and nanoelectronic. Normally CNTs prepared by catalytic chemical vapor deposition using various types of template such as alumina, quartz, silicon and glass template. In this paper, Novel method was introduced to prepare A-CNTs which is combination between immersion and evaporation method. The align CNTs were successfully growth on Porous Silicon template (PSiT) without catalyst. Camphor oil is used as precursor and evaporation temperature is at 800 °C. The PSiT was prepared by photo-electrochemical anodization method. The surface morphology of PSiT layer and A-CNTs were studied using Field Emission Scanning Electron Microscope (FESEM).While Raman spectroscopy will be carried out to study the degree of crystallinity or graphitization of A-CNTs. The growth mechanism will be discussed in this paper. Stubby A-CNTs was successfully growth with 30 nm diameter and 250 nm length on PSiT without metal catalytic process. Meanwhile, this novel technique was found that PSiT is an ideal template for growing A-CNTs without metal catalyst assisted. This novel technique was capable to obtained carbon nanotubes without metal catalyst assisted and improves their purity of product with low cost.

Diameter controlled of carbon nanotubes synthesized on nanoporous silicon support

Carbon nanotubes (CNTs) have been successfully synthesized on nanoporous silicon template (NPSiT) using botanical source, camphor oil. Diameter of CNTs synthesized was controlled by pore size of NPSiT prepared by photo-electrochemical anodization method. The diameter of CNTs grown on different NPSiT corresponded to the pore diameter of NPSiT. FESEM images showed self-organized bundles of fiber-like structures of CNTs with diameter of around 20nm which were successfully grown directly on nanoporous silicon while raman spectra obtained ratio of ID/IG at 0.67.

Synthesis of Carbon Nanotubes from Palm Oil Precursor by Aerosol-Assisted Catalytic CVD Method

Carbon nanotubes were produced from the aerosol-assisted catalytic CVD method using palm oil as the precursor and ferrocene as the catalyst. The CNTs were yielded at optimized temperature of 700oC and the Field Emission Scanning Electron Microscope showed the image of CNTs produced. Raman Spectroscopy, energy dispersive X-ray and Thermogravimetric Analysis were then used to further study the Raman Spectra, purity and identification of samples.

Structural and Thermal Properties of ACNT by Modified Deposition Method: Growth Time Approach

The knowledge of fabrication method plays an important role in the preparation of aligned carbon nanotubes (ACNT) from natural hydrocarbon feedstock. Here ACNT were successfully synthesized by two-stage catalytic chemical vapor deposition method using organic oil (camphor oil) as a precursor. Synthesis was carried out at a fixed growth temperature of 800 °C and in different growth time: 10, 20, 30, 40, 50 and 60 minutes. The optimized condition for the growth of ACNT produced a small amount of by-product amorphous carbon and highly uniform crystal structure. The experimental results demonstrated that formation ACNT is also dependent on the growth time. The nanotubes were characterized by field emission scanning electron microscopy and micro-Raman spectroscopy. Thermal properties were evaluated by thermogravimetric analysis.