Morphology-controlled electrochemical sensing of environmental Cd and Pb ions on expanded graphite supported CeO nanomaterials.

Heavy metal ions (e.g., Cd and Pb) are widely existed in environment and highly toxic. Their convenient, sensitive, and selective determination is thus desirable. In this study, a novel electrochemical sensing interface is developed using the composite of CeO nanomaterials supported on expanded graphite as the sensitive materials. As-prepared CeO nanomaterials through a hydrothermal method feature different morphologies (e.g., nanocube, nanopolyhedra, and nanorod-shape). Electrocatalytic ability of this interface and sensing performance towards the monitoring of Cd and Pb ions rely on the morphology and structure of used CeO nanomaterial. The interface using nanorod-shape CeO nanomaterials supported on expanded graphite exhibits superior electrochemical activity, namely remarkable signal enhancement for the monitoring of Cd and Pb ions. The developed electrochemical sensor with this r-CeO/EG composite as the sensitive material delivers the detection limits of 0.39 and 0.21 μg L for Cd and Pb ions, respectively.