To obtain the crystalline structure

To obtain the crystalline structure and composition of the as-obtained samples, X-ray diffraction (RigakuSmartLab XRD Bruker D2 Phaser) and the X-ray photoelectron spectroscopy (XPS Physical Electronics PHI5802) were utilized.
The urchin-like ZnCo2O4 microspheres were examined by adsorption experiments of nitrogen, and adsorption-desorption isotherms of nitrogen were measured at 77 K on Tovok Quantachromeautosorb automated gas sorption system.
2.3. Electrochemical measurements
3. Results and discussion
3.1. Structure analysis
Fig. 2 presents schematically the formation process of the nickel foam supported urchin-like ZnCo2O4 microspheres.