Fig. 2. (a) XRD pattern; (b) Raman spectra of TiO2@Co3O4 microspheres; (c) morphology of TiO2 after calcination at 600 °C for 4 h; (d) morphology of TiO2@Co3O4 after calcination at 850 °C for 4 h; (e) TEM morphology and elements mapping of calcined TiO2@Co3O4; (f) interface between TiO2 and Co3O4 of TiO2@Co3O4 microspheres.
