Effect of mechanochemical treatment of supported catalysts on the CVD growth of carbon nanomaterials

Various morphologies of carbon nanotubes (CNTs) grown on the Fe(NO/sub 3/)/sub 3/-Al(OH)/sub 3/ mixtures have been observed. Fe(NO/sub 3/)/sub 3/-Al(OH)/sub 3/ mixtures prepared by impregnation method have been mechanochemically treated by the high energy grinding process using a mixer mill. Long grinding duration of Fe-Al(OH)/sub 3/ induced Al(OH)/sub 3/ to amorphous form and promoted both Fe(NO/sub 3/)/sub 3/ and Al(OH)/sub 3/ to agglomerate into spheres. With as-prepared unground and ground mixtures, CNTs were grown by thermal CVD under C/sub 2/H/sub 2/ and H/sub 2/ gases at 700/spl square/. As a result, CNTs grown on ground mixtures have a more uniform diameter than those of unground mixture. In addition to this, morphological changes of CNTs grown on unground and ground mixtures show that mechanochemical treatment for supported catalyst can act as the factor of growth control.