X ray photoelectron spectroscopy xps

The grafting of fluorinated groups onto the polysilazane backbone was confirmed using the ¹H-NMR spectra obtained using a 300 MHz (Bruker, Billerica, MA, USA) spectrometer in a CDCl₃ solution. The Fourier-transform infrared (FTIR) spectra of the samples were obtained in the attenuated total reflection mode using a Nicolet 6700 (Thermo Scientific, Waltham, MA, USA) apparatus. The surface morphologies of the samples were evaluated using a field-emission scanning electron microscope (JSM-6701F, JEOL, Tokyo, Japan) at an acceleration voltage of 5 kV; the samples were sputter-coated with Pt prior to analysis. The chemical compositions of the coated surfaces were determined using an X-ray photoelectron spectroscopy (XPS; Thermo Scientific, Waltham, MA, USA) instrument with a monochromatic Al Kα X-ray source at a photon energy of 1486.7 eV. The CA and sliding angle (SA) of the coatings were measured using a Smart Drop (Femtobiomed, Seongnam, Korea) electronic device. A water droplet (8 µL) was placed on the coated surface at 25 °C, and the CA and SA were measured using the sessile drop method. The SA values were obtained by measuring the tilt angle of the coating where the water droplet slid off the surface at a tilt step of 0.2°. The reported CA and SA values are the averages of five measurements at different locations on each surface.

Numerous morphological and structural analyses were conducted. An X-ray diffractometer (X'PERT-Pro M.P.D., Netherlands) was used to assess crystallinity. The morphology was investigated using transmission electron microscopy (TEM). Thermo fisher scientific DXR was used for Raman analysis. Atomic force microscopy (AFM) was provided by nanoscience analytical to examine the thin sheets. A detailed microstructural analysis was performed using Thermo Fisher Scientific’s X-ray photoelectron spectroscopy (XPS).

The characterization of the catalyst mainly included crystal structure, microscopic morphology, element composition, and pore size distribution. The X-ray diffractometer model DX-2700 (Dandong Fangyuan Instrument Co. LTD, Dandong, China) was used for testing. The X-ray tube was copper palladium (λ = 1.5417 Å), the scanning step width was 0.02°, and the scanning angle was 10°~80°. The tube voltage and tube current were set to 40 kV and 30 mA, respectively. A scanning electron microscope (SEM, Zeiss SIGMA 300 field-emission, Oberkochen, Germany) characterized the microscopic morphology of the catalyst. Transmission electron microscopy (TEM) (FEI Tecnai G2 F20, FEI, Eindhoven, The Netherlands) collected information at a voltage of 200 kV. An inductively coupled plasma optical emission spectrometer (ICP-OES) measurement was performed with Agilent 720ES (Santa Clara, CA, USA), and the actual proportion of iron in the catalyst with different iron precursor content was determined. The K-Alpha type of Thermo Scientific (Waltham, MA, USA) was used to test the catalyst to obtain the valence state and surface energy state distribution of the catalyst by analyzing the X-ray photoelectron spectroscopy (XPS) (Thermo Scientific, Waltham, MA, USA).