CERAMICS INTERNATIONAL Available online at www.sciencedirect.com Ceramics International 41 (2015) 8809–8813 Magnesiothermal synthesis of nanostructured SiC from natural zeolite (clinoptilolite) and mesoporous carbon CMK-1 Behnam Hosseini a , Amir Abbas Nourbakhsh a,n , Kenneth J.D. MacKenzie b,n a Department of Materials Engineering, Shahreza Branch, Islamic Azad University, Shahreza, Esfahan, Iran b MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington, New Zealand Received 1 March 2015; received in revised form 21 March 2015; accepted 22 March 2015 Available online 27 March 2015 Abstract Magnesiothermal synthesis of nanosized SiC has been successfully achieved from a mixture of the natural zeolite clinoptilolite and a high- surface area mesoporous carbon CMK-1, synthesized by impregnating a mesoporous silica template MCM-48 with sucrose, followed by carbonization in argon and removal of the silica template. Magnesium powder was used to initiate the self-combustion reaction. Removal of the alkaline and alkaline earth exchangeable cations from the clinoptilolite by ion exchange with NH 4 þ was essential for a good yield of product, which is also dependent on the use of excess of carbon. TEM confirmed the nanostructure and size of the 15–25 nm SiC product crystallites. & 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Keywords: Nanostructured silicon carbide; Mesoporous carbon; Clinoptilolite zeolite; Magnesiothermal synthesis 1. Introduction Silicon carbide has many applications because of its high thermal conductivity, oxidation resistance, mechanical strength at high tem- perature and corrosion resistance. These properties have led to its use as biomaterials, high temperature semiconductor devices and catalysts. SiC with an average surface area of 20–100 m 2 /g is par- ticularly promising as a heterogeneous catalyst, leading to consi- derable research on the synthesis of SiC of high speci fic surface area [1], with a focus on the pore size and size distribution. Carbothermal reduction is a common method for synthesizing non-oxide materials such as SiC, particularly using nanostructured starting materials such as microporous zeolites and porous carbon with a high speci fic area. Such mesoporous carbons suitable for this purpose have been synthesized using mesoporous silicate templates with various struc- tures, including MCM-48, HMS, SBA-15 and MCF [2] . Zeolites are materials with tetragonal structures based on tetrahedral TO 4 units, where T can be a trivalent element such as Al, B, Ga or a tetrahedral element such as Ge and Si, the tetrahedral atoms connected through shared oxygens. Nanostructured SiC powder with a high specific surface area can be prepared by direct reaction of silicon with mesoporous carbon at 41200 1C [3,4,5], or by infiltrating silicon polymers into a mesoporous silicate structure and firing at 1000–1400 1C to obtain mesoporous SiC by carbothermal reduction [6, 7]. Problems related to control of grain growth and sintering make it difficult to produce porous SiC at high temperatures, militating against the formation of ordered structures [8]. An alternative method for synthesizing mesoporous SiC is by magnesiothermal reduction of nanostruc- tured SiO 2 /C composites at low temperatures (about 700–750 1C) [8, 9]. Hemmatian produced mesoporous SiC using MCM-48 as a silica template to produce mesoporous carbon by impregnating it with polyacrylamide, followed by magnesiothermal reduction [10]. Mojarad et al. also synthesized SiC with a high speci fic surface area by magnesiothermal reduction of zeolite ZSM-5 using a mesoporous carbon prepared by impregnation with furfuryl alcohol as the carbon source [11] . The present study explores the possibility of magnesiothermal synthesis of nanostructured SiC using a natural zeolite (clin- optilolite) as precursor rather than the more expensive ZSM-5, and mesoporous silica MCM-48 impregnated with sucrose as www.elsevier.com/locate/ceramint http://dx.doi.org/10.1016/j.ceramint.2015.03.107 0272-8842/& 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved. n Corresponding authors. E-mail addresses: anourbakhs@yahoo.com (A.A. Nourbakhsh), kenneth.mackenzie@vuw.ac.nz (K.J.D. MacKenzie).