S 4800

TNS and plasma-TNS surface topography were evaluated by SEM (S-4800, Shimadzu, Kyoto, Japan) with 10 kV accelerating voltage. AFM (SPM-9600, Shimadzu Co., Tokyo, Japan) was utilized to assay the mean average surface roughness (Ra), mean peak-to-valley height (Rz), surface profiles and three-dimensional surface topography of the samples. The sample chemical composition was determined by XPS (Kratos Axis Ultra, Shimadzu, Japan). Sample surface wettability was evaluated using a contact angle measurement system (VSA 2500 XE; AST Products, Billerica, MA, USA).

The surface topography of TNS samples was qualitatively evaluated by SEM (S-4800 Shimadzu, Kyoto, Japan) and SPM (SPM-9600; Shimadzu). The composition of the coating was analyzed by XPS using a Kratos Analytical Axis Ultra DLD electron spectrometer (Kratos Instruments, Manchester, UK) with a monochromatic Al Kα X-ray source. Each sample was etched with Ar ions for 2 min (evaporation rate of 5 nm/min) to remove surface contaminants. The surface phase properties were investigated by TF-XRD (RINT-2500; Rigaku, Tokyo, Japan). Spectra were recorded in the range of 2θ = 20°–50°, operating at 50 kV and 300 mA, using a Cu-Kα radiation source, scanning speed of 2°/min, and incident angle of 1°. Contact-angle measurements were performed using a video contact-angle measurement system (VSA 2500 XE; AST Products, Tokyo, Japan) at room temperature. Ultrapure water was used for measurements.

The morphologies of the samples were investigated by SEM (S4800, Japan), TEM (JEM-2100F, Japan), AFM (Veeco dimension V, USA), XRD (D8 Advance, Germany), UV-vis diffuse reflectance spectra (Shimadzu UV2550, Japan), XPS (Thermo ESCALAB 250, USA), inductively coupled plasma-atomic (ICP) mass spectrometry (Atomscan Advantage, Germany), superconducting quantum interference device (Quantum Design MPMS–XL, USA), X-ray absorption near-edge structure (Beamline of BL12B of Nation al Syncrotron Radiation Laboratory, China), Theoretical calculations (National Super Computing Centre in Jinan, China).

Scanning electron microscopy (SEM; S-4800, Shimadzu, Kyoto, Japan) and scanning probe microscopy (SPM; SPM-9600, Shimadzu, Kyoto, Japan) were used to analyze the surface topology and roughness of the Ti-QCM sensors over an area of interest of 2.0 × 2.0 μm². X-ray photoelectron spectroscopy (XPS; ESCA 5600, Ulvac-Phi Inc., Kanagawa, Japan) was used to analyze the chemical composition of the surface of the Ti-QCM sensors. AlKα radiation (15 kV, 300 W) was used as the X-ray source. During XPS, Ar ion sputtering was used to determine the composition of the surface layer.
Contact angle measurements of the Ti-QCM sensors were performed using a video contact angle measurement system (SImage Entry 6; Excimer Inc., Kanagawa, Japan). The measurement was performed after 2.6 μL of distilled water was dropped immediately after the surface treatment on the Ti-QCM sensors. The contact angle was used as a simple measure of the surface energy and hydrophilic nature of the sensor surfaces.

The samples were characterized by OM (Olympus BX51), SEM (Hitachi S-4800, 2 kV), XPS (Kratos Analytical AXIS-Ultra with monochromatic Al Kα X-ray), XRD (Shimadzu Thin Film, using Cu Kα radiation at room temperature in the 2θ range of 10 ~ 90°), Raman spectroscopy (Renishaw, Invia Reflex, excitation light of ~514 nm), TEM (JEOL JEM-2100F LaB6; acceleration voltage, 200 kV), and AFM (Dimension Icon, Bruker). The LEEM and μ-XPS elemental mapping data were acquired at the X-ray photoemission electron microscopy end station of the 09U (Dreamline) beamline of the Shanghai Synchrotron Radiation Facility. High resolution STEM-HAADF images were obtained on an aberration corrected transmission electron microscope JEM-ARM200F equipped with cold field emission gun with acceleration voltage of 200 kV.

The samples were characterized by Raman spectroscopy (Horiba, LabRAM HR‐800, 532 nm laser excitation, 100× objective lens), SEM (Hitachi S‐4800, operating at 1 kV), XPS (Kratos Analytical Axis‐Ultra spectrometer using a monochromatic Al Kα X‐ray source), optical microscopy (Olympus DX51), Keithley 2001 multimeter (Tektronix, Inc.), and Fourier transform infrared (Nicolet 6700) spectrometer equipped with integrating sphere.

The samples were characterized by SEM (Hitachi S-4800, 5 kV), XPS (Kratos Analytical AXIS-Ultra with monochromatic Al Kα X-ray) and TEM (JEM-F200). C-PANI and PANI were polymerized directly onto the surface of carbon cloth as a working electrode. Samples for ex situ XPS measurements at different voltages were prepared in a nitrogen-filled glovebox, kept dry and removed for testing without the need for transport procedures. For in situ Raman testing, the Fe||C-PANI cell was assembled inside a nitrogen-filled glovebox using an in situ Raman spectroscopy electrochemical cell (C031-1, GaossUnion). All binding energy values of the XPS results were referenced to the C 1s peak of carbon at 284.8 eV. Raman spectroscopy (HORIBA iHR550, excitation light of ~633 nm) and FTIR spectra (Bruker Hyperion FTIR spectrometer). The spectral emittance of the devices was tested by an INVENIO-R (Bruker) FTIR spectrometer in the spectral range of 2.5–25 µm (equipped with an integrating sphere). The C-PANI for tTEM was scraped off the carbon cloth with a knife.