New Schiff base-carbon nanotube–nanosilica–ionic liquid as a high performance sensing material of a potentiometric sensor for nanomolar determination of cerium(III) ions

The ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [BMP]Tf2N, as the binder, multi-walled carbon nanotubes (MWCNTs), silica nanoparticles, graphite powder and also a new synthesized Schiff base have been used to fabricate a new carbon composite electrode with very attractive sensing behavior. New Schiff base, (Z)-2-((1H-1,2,4-triazol-3-ylimino)methyl)phenol, was synthesized to apply as an efficient ionophore in electrochemical responses of the potentiometric sensor for the determination of Ce(III) ions in aqueous solutions. This potentiometric sensor responds to Ce(III) ions in the wide linear range of 2.00 × 10−8 to 1.00 × 10−1 mol L−1 with a Nernstian slope of 19.79 ± 0.10 mV decade−1. The detection limit of 6.45 × 10−9 mol L−1 was obtained at pH range 3.0–7.5. It has a fast response with response time of about 5 s, and can be used for at least 17 weeks without any considerable divergences in the potentials. The proposed sensor thus allows sensitive, selective, simple, low-cost, and stable electrochemical sensing of Ce(III) ions in the presence of a large number of alkali, alkaline earth, transition and heavy metal ions. Such abilities promote new opportunities for determining Ce(III) ions in a wide range of real samples.