▎ 摘　　要

Graphene (reduction of graphite oxide, rGO) was successfully prepared by using ammonia solution (NH3H2O) as a reductive agent. The molecular structure and electrochemical properties of rGO were characterized by FTIR, XRD, Raman, SEM, EIS, and cyclic voltammetry (CV). The electrochemical sensing of chromium (Cr(VI)) at graphene-modified electrode (rGO/GCE) was investigated by differential pulse cathodic stripping voltammetry. The result showed that the charge transfer resistance of [Fe(CN)(6)](3-/4-) at rGO/GCE was 75.02 Omega cm(2) decreased by about nine times comparing as that of GCE. The reduction peak potential of Cr(VI) at rGO/GCE was shifted positively by 116 mV and the peak current increased by about eight times. Meanwhile, the detection limit was 1.5 x 10(-7) mol/L. It was worth noting that the synthesis of rGO by reducing GO with NH3H2O was more friendly to environment and human health relative to hydrazine hydrate (NH2-NH2H2O) or other poisonous reductants.