High quality Pt-graphene nanocomposites for efficient electrocatalytic nitrite sensing

A promising electrochemical sensor, Pt nanoparticles decorated on the surface of reduced graphene oxide (RGO) sheets were facilely synthesized by a one-pot hydrothermal method. The morphology and composition of as-prepared Pt-RGO composites have been characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and X-ray diffraction (XRD). It is found that Pt nanoparticles with ca. 4.81 +/- 1.54 nm in diameter were evenly distributed on the surface of RGO sheets. The cyclic voltammetry shows that Pt-RGO nanocomposite has a higher electron transfer rate and remarkable increase electrochemical activity toward the oxidation of nitrite. The amperometry reveals that the Pt-RGO modified electrode exists a good linear relationship between peak current and concentration of nitrite with a low detection limit of 0.1 mu M and high sensitivity of 496.4 mu A mM(-1). Moreover, the as-synthesized Pt-RGO electrode display a fast amperometric response within 4s. Compared to the bare Pt nanoparticles or the RGO modified glassy carbon (GC) electrode, the as-synthesized Pt-RGO nanocomposite shows a well reproducibility, stability and anti-interference electrocatalytic performance toward nitrite sensing. (C) 2015 Elsevier B.V. All rights reserved.