Su8100

The compositions and phases of the obtained samples were characterized by powder XRD on the PANalytical X’Pert diffractometer with a CuKα radiation. SEM (SU8100) and HRTEM (FEI Tecnai-F20) were used to characterize the shape and crystal structure. The surface compositions of samples were characterized by PHI QUANTUM2000 photoelectron spectrometer (XPS). N₂ adsorption/desorption isotherms were used to characterize the surface areas of samples based on the BET method (Micrometrics ASAP 2020 system). Bruker ESP-300E spectrometer was used to measure EPR spectra at 9.8 GHz with X-band and 100 Hz field modulation. Dynamic light scattering (DLS) experiments were conducted on a Nano-Zetasizer (Nano-ZS) from Malvern Instruments (Malvern, UK). The experimental process was as follows: samples (0.1 g) and ethanol (10 mL) were added into a glass bottle (15 mL) and dispersed uniformly by ultrasonication for 10 min. Solutions were placed at different times under agitation and non-agitation, respectively. Then, the upper liquids were taken for DLS tests.

The composition and phase of the as-prepared products were acquired by the powder X-ray diffraction (XRD) pattern using a Panalytical X-pert diffractometer with CuKα radiation. The morphology and crystal structure of as-prepared products were observed by scanning electron microscopy (SEM, SU8100), and high-resolution transmission electron microscopy (HRTEM, FEI Tecnai-F20) with an acceleration voltage of 200 kV. All TEM samples were prepared from depositing a drop of diluted suspensions in ethanol on a carbon film coated copper grid. Raman spectra of the material were collected with a micro-Raman system with 632.8 nm diode laser excitation on a 300 lines per mm grating at room temperature. PHI QUANTUM2000 photoelectron spectrometer (XPS) was using to characterize the surface compositions of product. The surface areas of these samples were measured by the Brunauer–Emmett–Teller (BET) method using nitrogen adsorption and desorption isotherms on a Micrometrics ASAP 2020 system.

The FIDF and FSDF powder samples were sputtered with gold under reduced pressure conditions. The morphological structures of the DFs were observed using a SU8100 cold field emission SEM (FEI Co., Hillsboro, OR, USA) at an acceleration voltage of 20 kV and a magnification coefficient of 10 k and 5 k.