Design and synthesis of CoMoO4–NiMoO4·xH2O bundles with improved electrochemical properties for supercapacitors

CoMoO4–NiMoO4·xH2O bundles with excellent electrochemical behavior were designed and synthesized by a facile strategy. CoMoO4 nanorods were fabricated by a chemical co-precipitation method, and then CoMoO4–NiMoO4·xH2O bundles were prepared by the same method using the CoMoO4 nanorods as the backbone material. A growth mechanism was proposed to explain the formation of the bundles. The composites combine the advantages of the good rate capability of CoMoO4 and the high specific capacitances of NiMoO4·xH2O, showing higher specific capacitances than CoMoO4 and a better rate capability than NiMoO4·xH2O. A maximum specific capacitance of 1039 F g−1 was achieved at a current density of 2.5 mA cm−2, and 72.3% of this value remained at a high current density of 100 mA cm−2. The excellent electrochemical performance makes the composite a promising electrode material for electrochemical capacitors.