fig3

Figure 3. Characterization of ZnCo₂O₄, Zn_1-xCo₂Ni_xO₄, ZnCo_2-yFe_yO₄ and Zn_1-xCo_2-yNi_xFe_yO₄. (A) Thermogravimetric analysis (TGA) of ZnCo-RDC, Zn-RDC, and Co-RDC; (B) X-ray diffraction (XRD) patterns; (C) Raman spectra; (D) Co 2p X-ray photoelectron spectroscopy (XPS) spectra; (E) Fe 2p XPS spectra; (F) Zn 2p XPS spectra; (G) Ni 2p XPS spectra; (H) N₂ adsorption-desorption isotherms; (I) Pore-size distribution. RDC: Rhombic dodecahedral cage.