A facile hydrothermal route to spinel CoCo2O4 nanotubes and porous nanostructures without assisted surfactants and templates

Spinel CoCo2O4 nanotubes and porous nanostructures have been synthesized by a novel hydrothermal method from Co(NO3)2·6H2O in mixtures of ammonia and cyclohexane at 220 °C. The morphology and phase of CoCo2O4 can be controlled by adjusting the experimental parameters that include the Co2+ concentration and the volume ratio of ammonia to cyclohexane. X-ray diffraction and transmission electron microscopy analyses were used to characterize the products. The formation mechanisms of CoCo2O4 nanostructures is proposed in detail. The electrochemical properties of the as-prepared samples have been investigated.