CdO nanoparticles: robust inorganic additive for cadmium selective polymeric electrode based on N-phenylaza-15-crown-5

This study presents the development of a new and sensitive polyvinyl chloride electrode based on cadmium oxide (CdO) nanoparticles and N-phenylaza-15-crown-5 for the selective determination of cadmium cations. To this end, synthesized cadmium oxide nanoparticles were characterized through XRD, FT-IR and FESEM analysis. Then, CdO nanoparticles were applied as a modifier for the fabrication of the proposed electrode. The optimum membrane composition to construct the electrode comprised poly(vinyl chloride) (30%), nitrobenzene (61%), cadmium oxide nanoparticle (3%) and N-phenylaza-15-crown-5 (6%). The Nernstian slope of the electrode was obtained 27.3 +/- 0.3 mV/decade in the 1.0 x 10(-8) to 1.0 x 10(-1) M concentration range, and the detection limit was obtained as 9.8 x 10(-9) M. The response time of the electrode was short (5 s), while its reversibility and lifetime were high. It was revealed that the operation pH range of the electrode ranged between 2 and 9, and the electrode had a very good selectivity to cadmium cations among the other interfering ions. Further, the electrode was successfully used as a potentiometric sensor in complexometric titrations and the measurement of cadmium cations in the environmental waters.