Facile Preparation of Graphene/Polyaniline Composite and Its Application for Electrocatalysis Hexavalent Chromium Reduction

•A graphene–polyaniline composite were simply synthesized.•The composite possesses high sensitive response to Cr(VI).•The composite presents exceptional catalytic property toward Cr(VI) reduction.•A base for developing attractive material for wide application was provided. 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.