Synthesis of silicon carbide nanomaterials by microwave heating: Effect of types of carbon nanotubes

Journal Pre-proof Synthesis of Silicon Carbide Nanomaterials by Microwave Heating: Effect of Types of Carbon Nanotubes

V.C.S. Tony, C.H. Voon, B.Y. Lim, Y. Al-Douri, S.C.B. Gopinath, M.K.Md Arshad, S.T. Ten, N.A. Parmin, A.R. Ruslinda PII:

S1293-2558(19)30692-2

DOI:

https://doi.org/10.1016/j.solidstatesciences.2019.106023

Reference:

SSSCIE 106023

To appear in:

Solid State Sciences

Received Date:

11 June 2019

Accepted Date:

30 September 2019

Please cite this article as: V.C.S. Tony, C.H. Voon, B.Y. Lim, Y. Al-Douri, S.C.B. Gopinath, M.K.Md Arshad, S.T. Ten, N.A. Parmin, A.R. Ruslinda, Synthesis of Silicon Carbide Nanomaterials by Microwave Heating: Effect of Types of Carbon Nanotubes, Solid State Sciences (2019), https://doi. org/10.1016/j.solidstatesciences.2019.106023

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier.

Journal Pre-proof

Synthesis of Silicon Carbide Nanomaterials by Microwave Heating: Effect of Types of Carbon Nanotubes V.C.S. Tony1, C. H. Voon1*, B.Y. Lim2, Y. Al-Douri3,4,5, S. C. B. Gopinath1, 6, M. K. Md Arshad1, S. T. Ten7, N.A. Parmin1, A.R. Ruslinda1 1Institute

of Nano Electronic Engineering, University Malaysia Perlis, 01000, Kangar, Perlis, Malaysia.

2School

of Materials Engineering, University Malaysia Perlis, Jejawi, 02600 Arau, Perlis, Malaysia. 3University

4Nanotechnology

Research Center, Cihan University Sulaimaniya - 46002, Iraq

and Catalysis Research Center (NANOCAT), University of Malaya, 50603 Kuala Lumpur, Malaysia.

5Department

of Mechatronics Engineering, Faculty of Engineering and Natural Sciences, Bahcesehir University, 34349 Besiktas, Istanbul, Turkey

6School

of Bioprocess Engineering, University Malaysia Perlis, 02600 Arau, Perlis, Malaysia.

7Malaysian

Agricultural Research and Development Institute, Serdang 43400, Malaysia *E-mail: [email protected]

Abstract One-dimensional silicon carbide nanomaterial (SiCNM) is the leading potential material for high temperature, high power and harsh environment components and devices. This is due to the outstanding properties of the one-dimensional SiCNMs such as high mechanical properties, high hardness, good chemical inertness and excellent electronic properties. In this paper, we reported the successful synthesis of one-dimensional SiCNMs from blend of SiO2 particles with two types of CNTs, namely MWCNTs and SWCNTs by using microwave heating and the effect of types of CNTs on the synthesis of one-dimensional SiCNMs. The result of x-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy and thermo-gravimetric analysis revealed that high purity of β-SiC nanotube was obtained from blend of SiO2 particles and MWCNTs while solid SiC nanowire was synthesized from blend of SiO2 particles and SWCNTs and associated with the presence of residual of unreacted SiO2 particles. This clearly shows that types of one dimensional SiCNMs (hollow or solid) can be controlled by

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Journal Pre-proof using different types of CNTs and thus this study proposed a high efficiency microwave heating method for the synthesis of one-dimensional SiCNMs with controllable morphology. Keywords: SiC nanomaterials; microwaves synthesis; gas-solid reactions; carbon nanotubes; nanowires

1. Introduction

In recent decades, CNTs has been thoroughly investigated by many researchers due to the extraordinary properties exhibited by CNTs such as high mechanical strength, high thermal conductivity and electrical properties [1, 2]. These properties have allowed the applications of CNTs in many important areas including structural [3], electronics [4], field emission [5] and energy storage [6]. However, limitation of CNTs such as low thermal and oxidation stability has limited the applications of CNTs in the high temperature, high power and harsh environment electronics. Silicon carbide nanomaterial (SiCNMs) are expected to have advantages over the bulk SiC because their shape effects, low dimensionality and quantum confinement has improved the properties and expand the applications of SiCNMs in many fields [7]. SiCNMs especially silicon carbide nanotubes (SiCNTs) and nanowires (SiCNWs) has shown high potential in the applications of high frequency, high-power and harsh environment electronics due to their outstanding properties including chemical inertness, high thermal stability and high mechanical and hardness [8, 9]. Currently, SiCNTs are mainly synthesized through carborthermal reduction of silica using conventional heating and CVD method as reported by Quah et al. [10] and Xie et al. [11]. Unfortunately, these methods have showed some downsides which affected quality of the SiCNTs. For example, SiCNTs has been successfully synthesized from carbothermal reduction of silica by using conventional heating at 1200 °C to 1250 °C for 15 to 24 hours as reported by Keller et al. [12]. However, heating duration of 15 to 24 hours was not energy efficient since it causes large consumption of energy to maintain such a long heating duration and thus incurs high production cost. Meanwhile, only small amounts of SiCNTs were synthesized by using CVD method and impurities often associates with the product. For SiCNWs, CVD [13], carbothermal reduction [14] and combustion synthesis [15] were most widely used for the synthesis of SiCNWs in which these methods 2

Journal Pre-proof possess different disadvantages. For example, synthesis of SiCNWs by CVD generally requires catalyst [13, 16] or gaseous precursors [17]. Although synthesis of SiCNWs by combustion method can be conducted at relatively low temperature within shorter duration, the as synthesized SiCNWs were associated with irregular morphologies and considerable amount of impurities which required further purification [15, 18]. Synthesis of SiCNWs using carbothermal reduction methods by conventional heating generally associated with high temperature and long heating duration [14, 19-21]. Special characteristics of the microwave heating which can volumetrically heat materials with shorter time at low cost has been discovered and applied by many researchers for the effective synthesis of SiC [22, 23]. For example, Li et al [24] has reported the successful synthesis of the single-phase SiC nanoparticles and nanowhiskers in argon atmosphere by using the microwave heating. They also revealed that microwave heating is a more effective synthesis method for the synthesis of SiC compared to conventional heating in terms of time saving and low energy consumptions. Microwave is electromagnetic wave with frequency ranges from 300 MHz to 300 GHz and materials with dielectric properties such as carbon can effectively couple with microwave and thus absorbs microwave energy which then volumetrically produces heat from the inside of materials [25]. Meanwhile, transfer of the heat energy through the mechanism of the conduction, convection and radiation was generally used in the conventional heating and the heat loss and irregular heat transfer from heat source to materials frequently occurs which results in the consumption of high energy and low heating rate [26]. Compared to conventional heating, microwave heating has higher heating rate, shorter reaction time, lower consumption of energy and the product has higher purity. In this article, SiCNMs, namely SiCNTs and SiCNWs were synthesized from two types of CNTs which are MWCNTs and SWCNTs, respectively. To the best of our knowledge, there is no study relating the types of CNTs on the final morphology of SiCNMs. Several researchers have reported the significant effect of the starting materials on the synthesis of SiCNMs [27, 28]. For example, Taghavi et al [29] reported the synthesis of SiC by using carbon black and petroleum coke as carbon sources. They revealed that SiC nanoparticles was obtained when petroleum coke was used as carbon source while SiC nanofibers were formed when carbon black was used as carbon source. Thus, in this study, synthesis of the SiCNMs using different types of CNTs was conducted at temperature of 1400 °C with heating rate of 30 °C/minute and maintained for 40 minutes. The effect of different types of CNTs on the composition, morphology, optical and purity of the SiCNMs were discussed and reported. 3

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2. Experimental

MWCNTs and SiO2 particles used in this study were purchased from Sigma Aldrich while SWCNTs were purchased from Guangzhou Jiechuang Trading Co., Ltd. MWCNTs (diameter of 38 nm) was blended with SiO2 particles (particle size of 4 m) in the ratio of 3:1 by using ultrasonic bath for 2 hours with ethanol as liquid medium which then dried on the hot plate to remove ethanol and hand pressed into pellet with thickness of 3 mm for 5 minutes at 312.4 MPa by using Woodward Fab Shop Press 20 Ton. Similar steps were then repeated for the blend of SiO2 particles and SWCNTs (diameter of 10 nm). Multi-mode cavity microwave with 2.45 GHz power was used to conduct the microwave heating. Alumina crucible filled with silica sand, graphite, SiC susceptor and pellet of SiO2/MWCNTs in the ratio of 1:3 was placed into the microwave cavity as reported previously [30]. The temperature was increased to 1400 °C with heating rate of 30 °C/minute and maintained for 40 minutes. The sample was then left cooled in the microwave cavity until reached to room temperature. Similar steps were repeated for the pellet of blend of SiO2/SWCNTs. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy (EDX), photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR) and thermo-gravimetric analysis (TGA) were used to characterize the samples. Compositions of the samples were investigated by using XRD Siemens Diffractometer Model D-5000 with Cu Kα radiation source in θ/2θ mode. Measurements were taken at fast duration scan (1s) and small step size (0.02°) for XRD characterization. FESEM model Nova Nano 450 at magnification 200K and accelerating voltage of 5 kV was used to observed the morphology of the samples while elemental compositions of the samples was determined by using EDX model OXFORD FM29142. Philips Tecnai F20 Transmission Electron Microscopy (TEM) model was used to confirm the tubular structure of synthesized SiCNMs. PL FL3-11 J81040 with xenon lamp of 400 watt and excitation wavelength at 265 nm and FTIR MAGNA550 kBr spectroscopy was used to scan the samples from 500 to 4000 cm-1 with a spectrum resolution of 4 cm-1 to identify the optical properties of SiCNMs. Perkin-Elmer Pyris 6 TGA analyzer was used to evaluate the

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Journal Pre-proof thermal stability of SiCNMs. Samples weight of 10 mg were heated from 30 °C to 1300 °C with heating rate of 10 °C/minute in atmospheric air during the TGA analysis.

3. Results and Discussion 3.1. XRD Fig. 1 shows the XRD pattern of SiCNMs synthesized from blend of SiO2/MWCNTs and SiO2/SWCNTs. Both SiCNMs synthesized from blend of SiO2/MWCNTs and SiO2/SWCNTs show XRD peaks corresponded to β-SiC at 2 values of 36.5°, 41.2°, 60.5° and 72.7°, representing β-SiC planes of (111), (200), (220) and (311) and thus indicates the successful synthesis of β-SiC. Zhang et al. [31] reported similar result where XRD peaks corresponded to β-SiC nanofibres were observed at (111), (200), (220) and (311) planes associated with 2 values of 36°, 42°, 60° and 72°. It can be postulated that high yield of SiCNMs was obtained when MWCNT was used as carbon source as only very small XRD peak corresponded to SiO2 and carbon was observed at 2θ values of 21.3° and 27.2° as shown in Fig. 1 a). This shown that almost all SiO2 particles and MWCNTs were converted to SiCNMs. Barghi et al [32] reported similar observation where the XRD spectra of as synthesized SiCNTs shows on the peaks associated with β-SiC and no carbon nor Si diffractions were observed. Meanwhile, XRD peaks corresponded to residual of SiO2 particles and carbon were observed at 2θ values of 21.7° and 27.8°, associated with (101) and (002) planes of SiO2 particle and carbon in XRD pattern of SiCNMs synthesized from blend of SiO2/SWCNTs as shown in Fig. 1 b) indicating incomplete conversion of SiO2/SWCNTs to SiCNMs.

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Fig. 1. XRD pattern of SiCNMs synthesized from blend of a) SiO2/MWCNTs and b) SiO2/SWCNTs.

3.2. FESEM and EDX Fig. 2 shows the FESEM image of the MWCNTs, SWCNTs and SiO2 particles, respectively. The average diameters for MWCNTs and SWCNTs were 38 nm and 10 nm while the particles size of SiO2 particles is 4 m. SiO2 particles are agglomerates of smaller SiO2 particles which form larger particles as shown in Fig. 2 (c).

(a)

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b)

c)

Fig. 3 shows the FESEM images of SiCNMs synthesized from both blends of SiO2/MWCNTs and SiO2/SWCNTs. It can be observed that SiCNMs were observed in FESEM image of Fig. 3 a). The inset of EDX spectrum in Fig. 3 a) also revealed that only EDX peak corresponded to silicon and carbon were observed and indicated that only SiCNMs were produced and this may due to the amount of residual SiO2 particles and MWCNTs was too little to be observed. This is further supported by XRD pattern of SiCNMs synthesized from blend of SiO2/MWCNTs in Fig. 1 a) in which the intensity of peaks corresponded to SiO2 and carbon was very low. Meanwhile, SiO2 particles were observed in FESEM images of SiCNMs synthesized from blend of SiO2/SWCNTs as indicated by red arrow in Fig. 3 b) and EDX inset in Fig. 3 b) also revealed the presence of peak corresponded to oxygen, indicating the presence of SiO2 particles as by-product when blend of SiO2/SWCNTs was used. Furthermore, it can be observed that diameter of the SiCNMs synthesized from blend of SiO2/MWCNTs

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Journal Pre-proof was in the range of 13 to 71 nm while SiCNMs synthesized from SiO2/SWCNTs was in the range of 11 to 45 nm.

(a)

(b)

Fig. 3. FESEM images of a) SiCNTs synthesized from blend of a) SiO2/MWCNTs and b) SiO2/SWCNTs.

3.3. TEM

Fig. 4 shows the TEM images of SiCNMs synthesized from blend of SiO2/MWCNTs and SiO2/SWCNTs. TEM image in Fig. 4 a) show the SiCNMs has a hollow tubular structure, indicating SiC nanotube (SiCNTs) was synthesized from blend of SiO2/MWCNTs and it can also be observed that the interplanar spacing of SiCNTs was 0.26 nm. TEM image in Fig.4 b) shows that SiCNM has a solid nanowire structure, indicating SiC nanowire (SiCNWs) was 8

Journal Pre-proof synthesized from blend of SiO2/SWCNTs. The interplanar spacing of SiCNW synthesized from blend of SiO2/SWCNTs was measured to be 0.26 nm. Interplanar spacing of the SiCNWs was reported previously to be 0.26 nm [33] while interplanar spacing of MWCNTs and SWCNT was reported to be 0.35 nm [34, 35]. This indicated that during the microwave heating process in this study, both MWCNTs and SWCNTs have been succesfully converted to SiCNTs and SiCNWs, respectively.

(a)

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Fig. 4. TEM images of a) SiCNTs synthesized from blend of SiO2/MWCNTs and b) SiCNWs synthesized from blend of SiO2/SWCNTs.

3.4. PL PL spectra of the SiCNTs and SiCNWs synthesized from blend of SiO2/MWCNTs and SiO2/SWCNTs are showed in Fig. 5. It can be observed from PL spectrum of SiCNTs in Fig. 5 a) that only PL peak corresponded to β-SiC at wavelength of 460 nm was recorded and associated with energy band gap of 2.67 eV. This indicates that high purity SiCNTs was successfully obtained from blend of SiO2/MWCNTs. In contrast to the SiCNTs, other than PL peak attributed to SiCNWs, PL peak corresponded to SiO2 at wavelength of 390 nm and associated with energy band gap of 3.18 eV was also recorded in PL spectrum of SiCNWs in Fig. 5 b). This indicates SiO2 particle was present in the SiCNWs as impurity. This result also shown the agreement with XRD pattern and FESEM images of SiCNMs synthesized from both blend of SiO2/MWCNTs and SiO2/SWCNTs in Fig. 1 and 3. Munoz et al [36] reported similar result where they showed that there are presence of the SiO2 layer on the surface of SiC nanorods. It is also observed that the PL peak of both SiCNTs and SiCNWs were obviously blue-shifted compared to the energy band gap of bulk SiC (2.39 eV) [37] and this may be related to the effect of size confinement and defects of the SiCNMs. Renbing et al [7] also proposed that size, nanostructure, morphology and defects of the SiCNMs can affect the PL peak of the SiCNMs.

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Journal Pre-proof Fig. 5. PL spectra of a) SiCNTs synthesized from blend of SiO2/MWCNTs and b) SiCNWs synthesized from blend of SiO2/SWCNTs.

3.5. FTIR Fig. 6 show the FTIR spectra of SiCNMs synthesized from blend of SiO2/MWCNTs and SiO2/SWCNTs. From Fig. 5, absorption bands corresponded to Si-C bond are observed at at wavelength of 809.16 cm-1 and 800.24 cm-1 for both SiCNTs and SiCNWs, respectively. Similar result was also reported by Barghi et al [32] in their study of hydrogen sorption hysteresis and superior storage capacity of SiCNTs in which they reported the FTIR absorption band corresponded to Si-C bond was observed at wavelength of 796 cm-1. Mo et al [38] in their study of synthesis of SiC nanorods from CNTs also reported similar result where they recorded FTIR absorption band corresponded to Si-C bond at wavelength of 796 cm-1. It is worth mentioning that FTIR absorption band related to Si-O-Si band at wavelength of 494.83 cm-1 [39] and Si-O stretching band at wavelength of 1099.32 cm-1 [40] were observed in FTIR spectrum of SiCNWs in Fig. 6 b). This result is in good consistensy with the XRD pattern of SiCNWs in Fig. 1. FTIR absorption band at wavelength of 3435.81 cm-1 in Fig. 6 b) was associated with the OH group and is thought to due to mosture absorption during sample handling for FTIR testing.

Fig. 6. FTIR spectra of a) SiCNTs synthesized from blend of SiO2/MWCNTs and b) SiCNWs synthesized from blend of SiO2/SWCNTs.

3.6. Thermo-gravimetric Analysis (TGA) 11

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Fig. 7 shows the TGA curves of SiCNTs and SiCNWs synthesized from blend of SiO2/MWCNTs and SiO2/SWCNTs. It can be observed that the significant weight loss of about 4.5 - 5 wt % was recorded for both SiCNTs and SiCNWs. These weight losses commenced at 600 °C and ended at 750 °C and were attributed to the decomposition of trace amount of MWCNTs and SWCNTs. Similar result also reported by Mahajan et al [41] and Rosner et al [42]. In their studies, they reported that decomposition of the MWCNTs started at 400 °C and ended at 1000 °C while decomposition of the SWCNTs commenced at 500 °C and ended at 700 °C. Najafi et al [43] in their study of synthesis of SiC nano-powders using sol-gel method also reported the SiC nanopowders have 9 % weight loss due to the presence of free carbon which decomposed at temperature of higher than 600 °C.

Fig. 7. TGA curves of SiCNTs synthesized from blend of SiO2/MWCNTs and SiCNWs synthesized from blend of SiO2/SWCNTs.

3.7. Growth Mechanism of SiCNTs and SiCNWs Explanation of growth mechanism of SiCNMs including SiCNTs and SiCNWs by using model of vapor-liquid-solid (VLS), vapor-solid (VS) and solution-liquid-solid (SLS) has been proposed by various researchers [44-46]. In this article, VS mechanism was proposed to explain the formation of SiCNTs and SiCNWs from blend of SiO2/MWCNTs and SiO2/SWCNTs. Formation of SiCNTs and SiCNWs can be divided to three stages; microwave heating blend of SiO2/MWCNTs and SiO2/SWCNTs, vaporization of SiO2 particles into SiO gas and formation of SiCNTs and SiCNWs as illustrated in Fig. 8. 12

Journal Pre-proof The mechanism of formation of the SiCNTs from the reaction of SiO2 particles and MWCNTs was proposed in the author previous published work [30]. When SiO2/MWCNTs was subjected to microwave irradiation, MWCNTs absorbed microwave energy and produced heat by dielectric heating. SiO2 particles were heated by conduction and converted to SiO gas through the reaction between the SiO2 particles and MWCNTs as shown in Equation 3.1. SiCNTs were formed when the SiO gas further reacted with the remaining MWCNTs and released CO gas as the end gas product as shown by Equation 3.2. The nanotube structure of the MWCNTs was maintained after the reaction between MWCNTs and SiO gas. This is because the transformation of a MWCNTs to SiCNTs is controlled by the diffusion of Si, in this case SiO gas, to the SiC/C interface via surface diffusion [47]. Since MWCNTs have multi layers structure, a continuous supply of SiO gas is required for the formation of SiCNTs. This continuous diffusion of SiO gas is supplied by the reaction bewteen MWCNTs and SiO2 particles. Besides, since the transformation of MWCNTs to SiCNTs occurs from the outermost layer to the innermost layer, the multilayer structure of MWCNTs prevent the collapse of the MWCNTs during the transformation.

C (s) + SiO2 (s) = SiO (g) + CO (g)

(3.1)

2C (s) + SiO (g) = SiC (s) + CO (g)

(3.2)

3SiO (g) + CO (g) = SiC (s) + 2SiO2 (s)

(3.3)

In the case of the SWCNTs, instead of forming SiCNTs, SiCNWs were formed. The reactions between SiO2 and

SWCNTs

for the formation of SiCNWs are similar to those with

MWCNTs, however the structure of SWCNTs collapsed during the formation of SiO gas. This is because SWCNTs have single layer of carbon atom. Fig. 8 a) – e) shows the formation of the SiCNWs from blend of SiO2/SWCNTs. During the microwave heating, SWCNTs absorbed the microwave energy as indicated by red arrows in Fig. 8 a) and was heated up. SiO gas (green arrows) and CO gas (dark blue arrows) was produced from the reaction between SWCNTs and SiO2 as shown in Fig. 8 b), according to Equation 3.1. However, tubular nanotube structure of SWCNTs collapsed and formed carbon clusters (Fig. 8 (c)). SiO gas diffused and reacted with carbon clusters to form the SiC clusters as shown in Fig. 8 d). 13

Journal Pre-proof The remaining SiO gas and CO gas then tend to diffuse into the SiC clusters as indicated from Fig. 8 e) in which resulted in the growth of SiC nanowires from the reaction of SiO gas and CO gas according to Equation 3.3. Several researchers also reported similar occurrence where they reported the structural collapse of SWCNTs in the transformation process to other nanomaterials [36, 48]. Chiu et al. reported that attached SiC clusters at cathode become the SiC seed structure and allowed the epitaxial growth SiC nanowire and the growth of SiC nanowire is a catalyst free vapor-solid mechanism [49].

Fig. 8. Schematic for the growth mechanism of SiCNWs from blend of SiO2/SWCNTs by microwave heating.

4. Conclusions As a conclusion, SiCNTs and SiCNWs have been successfully synthesized from blend of SiO2/MWCNTs and SiO2/SWCNTs in the ratio of 1:3. XRD, FESEM, EDX, PL, FTIR and TGA have been used to characterize the SiCNTs and SiCNWs. The effect of different CNTs type (MWCNTs and SWCNTs) on the synthesis of SiCNMs was thoroughly investigated and reported in this study. SiCNT was successfully synthesized when blend of SiO2/MWCNTs was used while SiCNW together with small amount of SiO2 were formed when blend of SiO2/SWCNTs was used. The difference in the morphology of SiCNMs in this study is due to 14

Journal Pre-proof the different structure of starting materials of CNTs in which MWCNT has a multiple rolled concentric sheets of carbon and SWCNT has only rolled sheet of carbon. Multiple layer structure of MWCNTs enable the transformation of MWCNTs to SiCNTs while SWCNTs collapsed during the transformation led to the formation of SiCNWs.

Acknowledgments This work was supported by the Department of Higher Education, Ministry of Higher Education, and Malaysia [FRGS 9003-00441].

Conflicts of Interest The authors declare that they have no conflict of interest.

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Conflict of Interest and Authorship Conformation Form For Submission to Solid State Sciences Synthesis of Silicon Carbide Nanomaterials by Microwave Heating: Effect of Types of Carbon Nanotubes submitted V.C.S. Tony, C. H. Voon, B.Y. Lim, Y. Al-Douri, S. C. B. Gopinath, M. K. Md Arshad, S. T. Ten, N.A. Parmin, A.R. Ruslinda o

All authors have participated in (a) conception and design, or analysis and interpretation of the data; (b) drafting the article or revising it critically for important intellectual content; and (c) approval of the final version.

o

This manuscript has not been submitted to, nor is under review at, another journal or other publishing venue.

o

The authors have no affiliation with any organization with a direct or indirect financial interest in the subject matter discussed in the manuscript

Voon Chun Hong Institute of Nano Electronic Engineering (INEE) Universiti Malaysia Perlis (UniMAP) Jalan Kangar-Alor Setar, Seriab 01000 Kangar, Perlis, Malaysia +60179427832 [email protected]

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The highlights for this study are:  -silicon carbide nanomaterials can be produced by microwaves heating with significantly shortened processing time.  The processing is simple, involves only ultrasonic mixing and microwave heating.  Morphology of SiC nanomaterials (hollow or solid) can be controlled by using different types of CNTs.  SiC nanowires were formed when single walled carbon nanotube was used, while SiC nanotubes were formed when multiwalled carbon nanotube was used.  The formation mechanism for SiC nanowires and SiC nanotubes were proposed.  The morphology of one dimensional SiCNMs