Herein, graphene-polyaniline (GR-PANI) composite were synthesized via a combination of electrochemical polymerization and chemical technique. This in-situ approach allows GR and PANI to combine efficiently and anchor on electrode steadily, and the attractive interactions enable GR-PANI to provide superior electrochemical activities on the basis of their respective functionalities. Detailed electrochemical studies indicate that the GR-PANI possesses high sensitive response to Cr(VI) and presents exceptional electrocatalytic performance toward Cr(VI) reduction, which is attributed to the increasing amount of active sites on the GR-PANI modified electrode and the effective electron transfer behavior on GR-PANI/Cr(VI) interface. (C) 2014 Elsevier Ltd. All rights reserved.