One-step Bridging of g-C3N4 and Graphene Oxide by Successive Electrolysis for Constructing Electrochemical Sensor of Pb2+

Abstract

Synthesis methods of composites materials can tailor individual materials properties and make the composite possess more superior performance than individual materials. Herein, by combining –NH 2 group in graphitic carbon nitride (g-C 3 N 4 ) and a facile electrolytic route, g-C 3 N 4 -bridging reduced graphene oxide nanocomposite (g-C 3 N 4 /r-GO) was successfully prepared to construct chemical sensor for detection of Pb 2+ . Because g-C 3 N 4 contains a large amount of –NH 2 group, covalent bonds as bridges between GO and g-C 3 N 4 could be successfully formed by successively electrolyzing, which simultaneously induced removal of electron withdrawing group in r-GO. Such bridges could shorten the planar distance between GO and g-C 3 N 4 in comparison with the conventional π-π stacking, improving the electrochemical performance of r-GO and g-C 3 N 4 . Moreover, the above unique chemical structure of g-C 3 N 4 /r-GO not only exhibited excellent electrical conductivity but also provided plenty active sites to chelate Pb 2+ from solution. Therefore, the prepared g-C 3 N 4 /r-GO ensured chemical sensor for Pb 2+ detection with wide linear range (1.0–300 μg/L) and low detection limit (0.15 μg/L at S / N = 3). This simple method could also be extended to preparation of other elements-contained nanomaterials functionalized oxide graphene for improve its properties and widen its potential applications. Covalent bonds as bridges between GO and g-C 3 N 4 was successfully formed by successively electrolyzing which simultaneously induce removal of electron withdrawing group in GO. Such bridges can shorten the planar distance between r-GO and g-C 3 N 4 in comparison with the conventional π-π stacking, improving the electrochemical performance of the r-GO and g-C 3 N 4 . The prepared g-C 3 N 4 /r-GO not only exhibited excellent the electrical conductivity but also provided plenty active sites to chelate Pb 2+ from solution.