Escalab 250xi

Scanning electron microscope (SEM) images were obtained by JEOL JSM6510. TEM images were obtained by JEOL JEM‐ARM300F. The spherical aberration‐corrected atomic resolution TEM images were obtained by Hitachi‐HF5000. X‐ray diffraction (XRD) characterization was carried out by Bruker D8 advanced diffractometer operating with Cu Kα radiation. The electrical properties measured in the temperature range of 230–300 K were performed using a Quantum Design physical properties measurement system (PPMS). XPS measurements were run on a Thermo Scientific Escalab 250Xi. UPS measurements were performed on a Thermo Scientific Escalab 250Xi. The X‐ray absorption spectra (XAS) including XANES and EXAFS of the sample were collected at the Beamline of TPS44A1 in National Synchrotron Radiation Research Center (NSRRC), Taiwan. Raman spectra were obtained using a thermal dispersive spectrometer with laser excitation at 633 nm.

The separated precipitates from the aforementioned experiments were freeze-dried with a freeze dryer (SCIENTZ-10N, Ningbo Xinzhi Biotechnology Co., Ltd., Ningbo, China) for 24 h for surface characterization with X-ray energy spectrometer (EDS, ESCALAB 250Xi, Thermo Fisher Scientific Co., Ltd., Waltham, MA, USA), X-ray diffractometer (XRD, smart lab 3 kw, RIGAKU Co., Ltd., Tokyo, Japan), and X-ray photoelectron spectrometer (XPS, ESCALAB 250Xi, Thermo Fisher Scientific Ltd., Waltham, MA, USA). EDS was used to characterize the appearance and element content of the solid samples. The precipitate was magnified 10,000 times or 12,000 times. More details can be found in the previous publication [40 (link)]. XRD could identify the surface crystalline phase properties. The precipitates were characterized by a diffractometer at 40 kV and 30 mA. The scanning range was 10~90°, with an interval of 0.02°. For XPS, the sample was compressed into 1 cm × 1 cm pellets and a full-spectrum analysis was performed with a monochromatic Alka excitation source (HV = 1486.6 eV, power = 150 W, beam diameter = 400 μm, and C1s were calibrated as 284.8 eV).

Greigite nanozyme was synthesized with hydrothermal synthesis method. First, 0.82 g FeCl₃•6H₂O was added into 40 mL ethylene glycol, stirring at room temperature for 30 min to ensure complete dissolving of FeCl₃. Then 3.6 g of NaOAc was added to the clear solution to dissolve it completely. Afterward, 0.65 g of NAC was added to the solution and again stirred thoroughly until completely dissolved. Finally, the clarified mixed solution was transferred to the reaction kettle and reacted at 200 °C for 12 h in the incubator. After natural cooling, greigite nanozyme was washed with ethanol and double distilled water respectively three times, and then lyophilized in a freeze dryer.
Morphological of greigite nanozyme was determined with a scanning electron microscope (SEM, S‐4800II, Hitachi) and transmission electron microscope (TEM, Tecnai 12, Philips). Powder X‐ray diffraction (XRD) patterns of the greigite nanozyme were obtained using a D8 Advance polycrystalline X‐ray diffractometer XRD (D8 Advance, Bruker AXS). X‐ray photoelectron spectroscopy (XPS) of greigite nanozyme was measured on an ESCALAB 250Xi X‐ray photoelectron spectrometer (ESCALAB 250Xi, Thermo Scientific) with a monochromatic Al Kα source. All XPS peaks were calibrated using C1s (284.8 eV) as the reference. Zeta potentials for greigite nanozyme suspensions were determined by a Malvern ZEN3690 Zeta sizer (Malvern, UK).

The crystalline structure of LNFO samples was identified using a Rigaku Laboratory X-ray diffractometry (XRD)-MiniFlex600 instrument. The source of radiation is Cu K ${\alpha }_1$ . The chemical valence state analysis of LNFO films was performed using X-ray photoelectron spectroscopy with Al K $\alpha$ radiation (XPS; ESCALAB250Xi, Thermo Fisher Scientific, USA). The energy band structure of LNFO samples was investigated by ultraviolet photoelectron spectroscopy (UPS) measurement, performed with the ESCALAB250Xi spectrometer of Thermo Fisher Scientific, USA. UPS measurement was performed using He I (21.22 eV) under a negative bias voltage ( $-$  5 V), and the spectra were calibrated against the silver Fermi level. The morphology of LNFO films was investigated by scanning electron microscopy (SEM; Quanta200, FEI, USA) and atomic force microscopy (AFM; Multimode 8, Bruker, GER). The RS performance of LNFO-based devices were monitored by an electrical measurement system, carrying the Keithley 2410 SourceMeter and a micromanipulated cryogenic probe system (ST-500-4TX-6PORTS, Janis Research, USA).

FT‐IR spectra were obtained by an FT‐IR spectrometer (TENSOR 27, BRUKER, Germany). Zeta potential of hydrogels was measured by using a Zetasizer Nano‐ZS PN3702 system (Malvern Instruments, Worcestershire, England). Surface morphology, internal structure, and element mapping of hydrogels were analyzed by using a field emission scanning electron microscope (FE‐SEM, Hitachi S‐4800) after lyophilization. XPS (Thermo‐VG Scientific ESCALAB 250Xi) with a standard Al Ka X‐ray source (1486.8 eV) was used to analyze the chemical structure. Self‐healing test was done by using a simple cut‐link model. Compressive, tensile, and adhesive tests were performed on a universal mechanical testing machine (WD‐5A, Guangzhou Experimental Instrument Factory, China). The adhesion performance of BCD/PDA/PAM hydrogels were proven by covering on human skin. The cell compatibility of the hydrogels was confirmed before the experiments. These experiments were carried out with the full, informed consent from human subjects.