Fig. 2. (a) XRD pattern of MgCo2O4 NCAs; (b) Nitrogen adsorption-desorption isotherms and pore size distribution of MgCo2O4 NCAs, MgCo2O4 powder and bare nickel foam; (c)
XPS general spectrum of MgCo2O4 NCAs; XPS survey scans of (d) Mg 1s, (e) Co 2p and (f) O1s.