Facile and controlled growth of SWCNT on well-dispersed Ni-SBA-15 for an efficient electro-catalytic oxidation of ascorbic acid, dopamine and uric acid

High-surface area and well-ordered mesoporous Ni incorporated SBA-15 (Ni-SBA-15) catalysts were synthesized following a controlled post synthesis grafting process. The activities of these catalysts were evaluated in the synthesis of uniform diameter single walled carbon nanotubes (SWCNTs) adopting high temperature methane pyrolysis under atmospheric pressure. The characteristics of SWCNTs were confirmed by X-ray diffraction, thermogravimetric analysis, transmission electron microscopy (TEM) and Raman spectroscopy. The TEM micrographs reveal that the SWCNTs were mostly entangled bundles with diameters of about 2–3 nm. Raman spectra prove that the SWCNTs synthesized at 900 °C posses low amount of amorphous/defected carbon with very low ID/IG ratio. The radial breathing mode Raman peaks confirm the formation of SWCNTs of <3 nm diameter. SWCNTs modified glassy carbon electrode (GCE) has been developed and tested in 0.1 M phosphate buffer solution of pH 4.5. The SWCNTs/GCE exhibits superior electro-catalytic activity toward ascorbic acid (AA), dopamine (DA) and uric acid (UA). Moreover, AA, DA, UA were oxidized separately at distinguishable potentials along with well defined peaks thereby making possible for simultaneous determination of each compound.

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► Well-ordered mesoporous Ni-SBA-15 catalytic template employed to grow SWCNTs.
► Radial breathing mode Raman spectrum confirms the formation of SWCNTs of <3 nm diameter.
► SWCNTs modified electrode was achieved via simple procedure.
► SWCNTs/GC electrode was successfully employed for simultaneous determination of AA, DA and UA.