Electroreduction of Nitroaromatic Compounds at Electrochemically Reduced Graphene Oxide Supported Bimetallic Ag@Pd Nanorods Modified Electrodes

The design and fabrication of nanostructured electrode with high activity at low cost are crucial elements in studying the toxicity of environmental pollutants. Here, we develop a combined step of generating Electrochemically Reduced Graphene Oxide (ERGO) nanosheets on the surface of the glassy carbon electrode where an effective seed mediated growth followed by a galvanic exchange process were introduced for the direct growth of Ag core-Pd shell nanorods (Ag-Pd NRDs). The resulting electrode possesses a large surface area, interconnected porous networks, uniform distribution of bimetallic Ag-Pd NRDs with extremely thin size of Pd generation and good electrical conductivity, which are highly desirable for the electrocatalytic reduction of nitroaromatic compounds (NACs). In the fabrication step, the shell like Cu at the bimetallic NRDs acts as a sacrificial template for forming a thin layer of Pd at Ag NRDs surface by redox replacement reaction. Thus, the resultant Ag@Pd NRDs on ERGO modified electrode was profoundly tested for the electrochemical sensing of NACs with high sensitivity, selectivity and a very low detection limit of 1.8 x 10(-11) M. Differential Pulse Voltammetry (DPV) was used to study the linear range of 4-nitroaniline (4-NA) between 1.0 x 10(-9) M and 1.2 x 10(-8) M. The modified electrode exhibits better reproducibility and long term stability. In addition, the modified electrode out performed well in the real sample analysis containing NACs in the presence of different interfering cations and anions.