Synergistically improved electrochemical performance and its practical application of graphene oxide stabilized nano Ag2S by one-pot homogeneous precipitation

Based on the high specific area and superior electrochemical property of graphene oxide and excellent electro-catalytic performance of Ag2S, graphene oxide stabilized nano Ag2S composite (GO-Ag2S) was proposed and constructed in this work by one-pot homogeneous precipitation. It was expected GO-Ag2S could possess special stability, dispersion and electrochemical activity, which were estimated by SEM, TEM, EDS, XRD, FT-IR, cyclic voltammetry and electrochemical impedance spectra. It was noted that there was a synergistically improved electrochemical performance between Ag2S and GO in as-prepared GO-Ag2S owing to their strong interactions. Especially, it exhibited an exclusively electrochemical response to heavy metal Hg2+ with high sensitivity once modified onto glassy carbon electrode (GCE). Under the optimized conditions, a wide liner range of 0.0-290.0 x 10(-10) mol/L and a low detection limit of 8.63 x 10(-12) mol/L for Hg2+ could be reached. Once applied for sensing Hg2+ in really environmental water samples and fruit juice samples, the recovery was between 95.5% and 105.7%. Mercury amalgam formed onto the surface of nano Ag2S was accordingly proposed for GO-Ag2S to recognize Hg2+ after the electro-catalytic redox of Hg2+.