Glucose-assisted synthesis of Co3O4 nanostructure with controllable morphologies from nanosheets to nanowires

Here, we develop a convenient route to obtain shape-controllable porous Co3O4 nanostructure from nanosheets to nanowires, which is realized with the assistance of additive glucose by a hydrothermal synthesis. Hydrothermal temperature, calcination temperature and additive glucose dosage significantly determine the morphologies of the final products. Upon the enhancement of additive glucose dosage, the shape of Co3O4 evolves from nanosheets in high aspect-ratio to dendritic nanowires. Meanwhile, a probable growth mechanism is proposed to explain the generation of various morphologies. Acting as electrode materials for pseudocapacitor application in 3 M KOH, the electrochemical performance of as-prepared Co3O4 nanomaterials are evaluated by cyclic voltammetry and chronopotentiometry tests. Compared with the resultant Co3O4 nanosheets materials, the obtained Co3O4 nanowires exhibit preferable pseudo-capacitive property with a higher specific capacitance and more satisfactory cycle stability. The optimal porous Co3O4 nanowire sample is prepared by heat-treatment at 300 °C with a cobalt salt/glucose mass ratio of 1:2, which exhibits a highest capacitance value of 471.8 F g−1 at 0.5 A g−1 and an excellent cycling stability with a ca. 94.8% capacitance retention after 1000 cycles at 2 A g−1.