XRD data were collected on a Rigaku MiniFlex 600 X-ray diffractometer. SEM images were obtained on a FEI QUANTA 450 electron microscope. The TEM images, aberration-corrected TEM images, HAADF-STEM imaging and EDS mapping were taken on a FEI Titan Themis 80-200 operating at 200 kV. X-ray photoelectron spectroscopy (XPS) analysis was carried out under ultrahigh vacuum (degree of vacuum about 5*10−9 m bar) on Thermo Scientific K-Alpha+ with mono Al Kα source in Voltage of 15 kV and energy of 1486.6 eV.
Synchrotron-based NEXAFS measurements were determined on the soft X-ray spectroscopy beamline at the Australian Synchrotron, which is equipped with a hemispherical electron analyzer and a microchannel plate detector to permit concurrent recording of the total electron, and partial electron yield. Calibration of XPS data was normalized to the photoelectron current of the photon beam, measured on an Au-grid. Raw XANES data were normalized using Igor Pro 8 software.
Synchrotron-based NEXAFS measurements were determined on the soft X-ray spectroscopy beamline at the Australian Synchrotron, which is equipped with a hemispherical electron analyzer and a microchannel plate detector to permit concurrent recording of the total electron, and partial electron yield. Calibration of XPS data was normalized to the photoelectron current of the photon beam, measured on an Au-grid. Raw XANES data were normalized using Igor Pro 8 software.