Jem 2010 high resolution tem

The morphology images were recorded on Zeiss SUPRA55 scanning electron microscope (SEM), which combined with energy‐dispersive X‐ray spectroscopy (EDX), and transmission electron microscopy (TEM) (Philips Tecnai 20 and JEOL JEM‐2010 high‐resolution TEM). The optical image was performed on a Leica DMI8 fluorescence microscope. X‐ray diffraction (XRD) data were performed on Shimadzu XRD‐6000 X‐ray diffractometer (Cu Kα radiation (0.154 nm) at 40 kV, 30 mA, and scanning rate of 10° min⁻¹). X‐ray photoelectron spectra (XPS) were performed on a Thermo VG ESCALAB 250 X‐ray photoelectron spectrometer (pressure: 2 × 10^–9 Pa; excitation source: Al Kα X‐rays). The aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) was performed on FEI Titan Cubed Themis G3 300. The Co K‐edge XAS data were collected at the beamline 1W1B of the Beijing Synchrotron Radiation Facility (BSRF), Institute of High Energy Physics (IHEP), and Chinese Academy of Sciences (CAS). Contact angle was performed by the sessile drop method in glove box. Crimping and shocking tests were carried out by tablet press (MTI, China) and vortex mixer (TAT, China).

TEM images were taken on a JEOL JEM-2010 high-resolution TEM with an accelerating voltage of 120 kV. The sample was stained with 1% sodium phosphotungstate solution at pH 7 before observation.