Abstract Spinel CoCo 2O 4 nanotubes and porous nanostructures have been synthesized by a novel hydrothermal method from Co(NO 3) 2·6H 2O in mixtures of ammonia and cyclohexane at 220 °C. The morphology and phase of CoCo 2O 4 can be controlled by adjusting the experimental parameters that include the Co 2+ 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 CoCo 2O 4 nanostructures is proposed in detail. The electrochemical properties of the as-prepared samples have been investigated.