Edx spectroscopy

X-ray diffraction (XRD) patterns of the LSCFP nanofibers were analyzed over a 2θ range of 20°–80° using a high-resolution X-ray diffractometer (Smartlab, Rigaku) with CuKα radiation (λ = 1.54 Å). The crystal structures were refined using Smartlab Studio II software package (Rigaku). The microstructure of the nanofibers and cell components was observed using field-emission scanning electron microscopy (FE-SEM, S-8230, Hitachi). Morphology and compositional properties of the LSCFP nanofibers were examined using high-resolution transmission electron microscopy (HR-TEM, Talos F200X, FEI) equipped with energy-dispersive X-ray (EDX) spectroscopy (Bruker). Surface oxidation states of the LSCFP nanofibers were analyzed by X-ray photoelectron spectroscopy (XPS, Nexsa G2, Thermo Fisher) with the CASA XPS software package. The CO₂-temperature programmed desorption (CO₂-TPD) was performed using an Autochem II 2920 (Micromeritics) equipped with a thermal conductivity detector. Measurements were conducted in a U-type quartz reactor using 0.2 g of sample. The sample was pre-treated in 50 sccm He at 400 °C for 1 h. Then, the CO₂ adsorption experiment was carried out in CO₂ of 50 sccm at 900 °C for 1 h. After cooling the sample to room temperature, the TPD curves were measured in 50 sccm He from room temperature to 900 °C.