Design and application of a polyoxometalate-ionic liquid-graphene oxide hybrid nanomaterial: New electrocatalyst for water oxidation

Design of a new hybrid nanomaterial, CoW12−IL−GO, is reported for utilization as an electrocatalyst for water oxidation reaction for oxygen evolution at neutral pH conditions. The desired electrocatalyst was prepared by covalent attachment of ionic liquid (IL) species to graphene oxide for preparing IL−GO and then electrostatic interaction of supported imidazolium cations with Keggin type [CoW12O40]6- polyanions. After confirming the construction of CoW12−IL−GO with different physicochemical techniques, its electrochemical properties was evaluated. The CoW12 −IL−GO exhibited a low onset potential of 1.3 V vs. NHE and low overpotential of 269 mV at 10 mA.cm−2 with a low Tafel slope of 92 mV.dec−1 at neutral pH. Eventually, the electrocatalytic activity of prepared CoW12−IL−GO was studied in water oxidation reaction which revealed its outstanding stability over 14 h and retention of catalytic activity even after 900 catalytic cycles.