Fabrication of high dispersion Pd/MWNTs nanocomposite and its electrocatalytic performance for bromate determination

Pd nanoparticles decorated multiwall carbon nanotubes (Pd/MWNTs) catalyst was synthesized by in situ chemical method and its application for the determination of bromate was investigated. The morphology and composition of the Pd/MWNTs catalyst was characterized by Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The analyses indicate that Pd nanoparticles in metallic-state were homogeneously deposited on MWNTs with an average diameter of 4.5 nm. The electrocatalytic activity of Pd/MWNTs for the reduction of bromate was investigated by cyclic voltammetry (CV). An obvious peak corresponding to the bromate reduction was obtained between 0.15 and −0.25 V. Effects of different factors including scan rate, temperature and initial concentration of bromate ions on bromate determination were studied as well. A good linear relationship between the values of reduction peak and bromate concentration was obtained. Chronoamperometric measurement showed that the Pd/MWNTs modified electrode could be successfully employed as an amperometric sensor for bromate in a wide concentration range (0.1–40 mM) within a short response time (5 s), and the sensitivity of this sensor is 768.08 μA mM−1 cm−2. The results reported herein indicate that the Pd/MWNTs have a potential application in fabrication of bromate detector.

► The Pd/MWNTs nanocomposite with good activity and stability was synthesized.
► The application of Pd/MWNTs for the determination of BrO3- was investigated.
► A BrO3- reduction peak between 0.15 and −0.25 V was obtained by CV measurement.
► Linear correlation between the peak intensity and Cbromate (0.1–40 mM) is good.
► The Pd/MWNTs electrode could be employed as an amperometric sensor for BrO3-.