One-Step Synthesis of AuPdNPs/ERGO Nanocomposite for Enhanced Electrochemical Sensing of Cr(VI) in Water

Abstract

One-step electrochemical approach for synthesis of AuPdNPs/ERGO nanocomposite has been developed for Cr(VI) sensing in water. The bimetallic AuPd nanoparticles and electrochemical reduced graphene oxide (ERGO) composite (AuPdNPs/ERGO) were reduced from H2PdCl4, HAuCl4 and GO mixed solution and deposited onto glass carbon electrode (GCE) through cyclic voltammetry, simultaneously. The bimetallic AuPdNPs were homogeneously modified on graphene nanosheets and characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) technique. Based on the voltammetric results, the bimetallic AuPdNPs/ERGO/GCE had higher catalytic activity for Cr(VI) determination, compared with AuNPs/GCE, PdNPs/GCE and ERGO/GCE obtained by the same method. The fabricated AuPdNPs/ERGO/GCE shows good relationship in two concentration ranges from 0.05 μM to 5 μM and 5 μM to 1000 μM, with a detection of 0.013 μM (at S/N = 3). In addition, the proposed modified electrode presents high selectivity, sensitivity and stability for Cr(VI) detection and a high recovery of more than 95% was obtained towards real water application, which makes it favorable for the further practical field monitoring.