Fig. 1

a XRD patterns of the as-prepared precursor and NiCo2O4 product before and after heat treatment at 450 °C. b TGA analysis of precursor under oxygen atmosphere with a heating rate of 10 °C min−1
a XRD patterns of the as-prepared precursor and NiCo2O4 product before and after heat treatment at 450 °C. b TGA analysis of precursor under oxygen atmosphere with a heating rate of 10 °C min−1