Development of gold-doped carbon foams as a sensitive electrochemical sensor for simultaneous determination of Pb (II) and Cu (II)

Abstract

A novel emulsion polymerization–carbonization method was developed to prepare high-temperature-stable (850°C) gold nanoparticle-doped carbon foams using phenolic resins as a carbon source and HAuCl4 as a gold source and acidic catalyst. As-prepared Au–CFs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), N2 adsorption and desorption analysis. The results indicate that the carbons have interconnected main macropores of nearly 5.0μm, mesopore of 3.6–21.9nm and specific surface areas of 347–654m2g−1. And the AuNPs inside the pores have the diameter of ∼7nm. Differential pulse anodic stripping voltammetry (DPASV) has been used for the detection of Pb2+ and Cu2+. Experimental parameters, including supporting electrolytes, pH value, deposition potential and deposition time were also studied. Under optimal conditions, the typical Au(5.4%)/CFs-modified gold electrode exhibits excellent electrochemical response in the co-detection of Pb2+ and Cu2+, with limits of detection of 5.2nM and 0.9nM (S/N=3), respectively. The limits of detection are much lower than the guideline value that given by the World Health Organization. Besides, the selectivity and interference were also investigated under the above optimal conditions. This study provides a novel method of fabrication of noble metal-decorated carbon-based materials for the construction of sensitive electrochemical sensors that meet the needs of environmental control.