Graphene nanoplatelet supported CeO2 nanocomposites towards electrocatalytic oxidation of multiple phenolic pollutants

Highlights: • Facile synthesis of CeO₂ nanocubes, nanopolyhedras and nanorods. • Morphology-dependent electrochemistry of CeO₂ nanostructures. • Sensitive and selective monitoring of different environmental pollutants. -- Abstract: To explore suitable sensing materials for sensitive and selective detection of phenolic pollutants, CeO₂ nanocubes, nanopolyhedras, and nanorods were synthesized by a hydrothermal method. These CeO₂ nanomaterials were further loaded on the support of graphene nanoplatelets. As-synthesized nanomaterials and nanocomposites were characterized using transmission electron microscopy, X-ray diffraction and Raman spectroscopy as well as electrochemical techniques including cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. The nanocomposite of graphene nanoplatelets with CeO₂ nanorods shows the highest electrochemical activity towards soluble species. Highly sensitive and selective determination of tetrabromobisphenol A, catechol, diethylstilbestrol, and nonylphenol was thus achieved at this nanocomposite based electrode. Their limits of detection were as low as 1.8, 42, 1.5 and 2.7 nM, respectively. Such an electrochemical sensor is thus promising for simple, fast and sensitive electrochemical determining of trace-leveled phenolic pollutants in water samples.