*2.3. Characterization*

Transmission electron microscope (TEM) analyses were conducted with a JEOL JEM 2011 transmission electron microscope at 200 kV. Scanning electron microscope (SEM) analyses were conducted with a JEOL JSM 6400 scanning electron microscope. The powder X-ray diffraction (PXRD) patterns of the prepared samples were collected using an X-ray diffractometer with Cu-Kα radiation (40 kV, 30 mA). The patterns were recorded in the region of 2θ from 10◦ to 80◦ with a scan step of 0.02◦. The chemical binding energies of the respective ions in the samples were measured using X-ray photoelectron spectroscopy (XPS, ESCALa-b220i-XL electron spectrometer, Thermo Fisher Scientific K-Alpha, UK) under 300-W Al-Kα radiation. The magnetic properties were measured with a vibrating sample magnetometer (VSM), a physical property measurement system, at 300 K, as a function of the applied magnetic field between −80 and 80 kOe. The ultraviolet–visible (UV–Vis) diffuse reflectance data were collected with a UV–Vis spectrophotometer (Evolution 201, Thermo Scientific) equipped with an integrated sphere.
