Fei tecnai g2 f20

Transmission electron microscopy (TEM, FEI Tecnai G2 F20, FEI Company, College Station, TX, USA), X-ray photoelectron spectroscopy (XPS, Thermo Fisher ESCALAB 250Xi, Waltham, MA, USA), and Fourier-transform infrared spectroscopy (FT-IR, Nicolet 5700 spectrometer, Madison, WI, USA) were employed to reveal the morphology, the chemical composition, and the chemical structures of the N, F-CDs, respectively. Ultraviolet-visible spectroscopy (UV-vis, UV-2550 Shimadzu, Kyoto, Japan) was employed to determine the absorption of CDs and chemicals. Fluorescence spectroscopy, fluorescence lifetime decay spectra, and quantum yield (Fluorolo^@-3 steady-state spectrofluorometer, HORIBA Scientific, Kyoto, Japan) were recorded to investigate the optical properties of the N, F-CDs.

Optical microscope (Nikon Eclipse LV100 ND) characterization was done on as-grown graphene on copper foil. After growth, the graphene/copper substrate was heated upto 180 °C on a hot plate for 2 min for better optical visualization. The graphene-free copper surface changes color due to oxidation at such temperature and the graphene-covered copper remains unchanged which helps to identify graphene flakes by color contrast difference.
Scanning electron microscopy SEM (SEM Magellan 400L XHR) operated at an acceleration voltage of 10 kV was used to characterize the morphology and shape evolution of graphene domain on copper foil. The crystalline structure of graphene was characterized with high resolution transmission electron microscopy (HRTEM FEi Tecnai G2 F20) operated at 200 kV after transferring the as-grown graphene to a TEM grid (see ESI for transfer techniques†).

Crystal structures of the Al_0.5NbZrTi_1.5Ta_0.8Ce_x alloys were analyzed by X-ray diffractometry (XRD, Bruker D8 Focus, Bruker, Karlsruhe, Germany) using Cu Kα target with 2θ between 20–80° and a scan step of 0.05°. The microstructures were examined by scanning electron microscopy (SEM, JEOL JSM 7200F, JEOL Ltd., Tokyo, Japan) equipped with energy-dispersive detectors (EDS, Oxford X-Max, Oxford Instruments, Abingdon, Britain). Fine-structure observations were conducted by transmission electron microscopy (TEM, FEI Tecnai G2 F20, FEI Company, Hillsboro, OR, USA) equipped with energy-dispersive detectors (EDS, XFlash 6|100, Bruker, Karlsruhe, Germany).

Human scalp HFs were fixed in a mixture of 2% glutaraldehyde and 2% paraformaldehyde in 0.1 M cacodylate buffer for 2 h at room temperature and then processed for TEM as described in the literature [47 (link)]. Briefly, the samples have been washed in cacodylate buffer (0.1 M, pH 7.4), postfixed for 2 h with 1% osmium tetroxide in the same buffer, extensively washed again, and then incubated overnight in a 0.5% uranyl acetate aqueous solution in the dark. After washing, the sections have been dehydrated in a graded alcohol series, and after a final dehydration in 100% propylene oxide, they have been infiltrated with low viscosity Spurr resin overnight and polymerized for 48 h at 65 °C. Sections of about 70 nm were cut with a diamond knife (DIATOME) on a Leica EM UC6 ultramicrotome. Bright field TEM images have been collected with a Schottky field-emission gun FEI Tecnai G2 F20 (FEI, USA) transmission electron microscope operating at an acceleration voltage of 200 kV and equipped with a 2k × 2k Gatan Ultrascan (Gatan, USA) charge coupled device (CCD).

X-ray-diffraction (XRD) analysis with Cu Kα radiation at 40 kV and 50 mA was carried out using a diffractometer (PANalytical X’pert, PANalytical B.V., Almelo, Holland). The samples’ morphology, size, composition, and structure were characterized using field-emission scanning electron microscopy (FE-SEM, TESCAN MARI3, Tescan Ltd., Brno, Czech) and transmission electron microscopy (TEM, FEI TECNAI G2 F20, FEI Co., Hillsboro, OR, USA), combined with energy-dispersive X-ray (EDX) spectroscopy. The samples were measured by XPS using an Al Kα (1486.6 eV) X-ray source on a spectrometer (ESCALAB 250XI, Thermo Fisher Scientific Co., Waltham, MA, USA). The C 1s peak at 284.6 eV was selected for energy calibration to eliminate sample charging during analysis. The adsorption–desorption isotherms of nitrogen were acquired on a surface-area analyzer (JW-BK200A, Beijing JWGB Sci. & Tech. Co., Ltd., Beijing, China) in which all samples were deaerated at 100 °C prior to measurement. Hydrogen adsorption experiment was characterized by adding 30 mg of active materials into 50 mL of 1 M hydrochloric acid solution. After the solution was stirred for 2 h, the centrifugation was carried out and the pH change of the supernatant was measured to determine the amount of hydrochloric acid adsorbed by the active materials.

The surface morphologies of the corroded Cu electrodes were observed with laser scanning confocal microscopy (LSCM, LEXT OLS4100, OLYMPUS, Tokyo, Japan) and field emission scanning electron microscopy (FE-SEM, Nova Nano-SEM450, FEI, Hillsboro, OR, USA). X-ray photoelectron spectroscopy (XPS, ESCALAB 250 Xi, Thermo Fisher Scientific, Bedford, MA, USA) was carried out to analyze the components of the corrosion products on the surface. The cross-section microstructure of the pits was analyzed by the combined use of FIB/SEM (Helios Nanolab 600i, FEI, Hillsboro, OR, USA). The dislocation configurations on the microstructure of the rolled Cu strips were observed by transmission electron microscopy (TEM, FEI Tecnai G2 F20, FEI, Hillsboro, OR, USA).

To evaluate the structure of composites in prepared and annealed states, X-ray diffraction (XRD, PANalytical B.V., Almelo, Netherlands) was employed. The instrument X’PERT-PRO MPD with Cu Kα radiation was used. For a determination of the W-Al reaction onset temperature during continuous heating, two prepared composites was studied by differential thermal analysis (NETZSCH DSC 404F3, NETZSCH-Gerätebau GmbH, Selb, Germany) and thermal expansion analysis (NETZSCH DIL 402PC, NETZSCH-Gerätebau GmbH, Selb, Germany). The samples were heated to 950 K with heating rate of 5 K/min under a high purity argon gas flow. Interfacial microstructures were examined and analyzed carefully by High Resolution Transmission Electron Microscope (FEI Tecnai G2 F20, FEI Company, Hillsboro, OR, USA) equipped with an energy dispersive spectroscopy (EDS, FEI Company, Hillsboro, OR, USA). Selected area electron diffraction (SAED, FEI Company, Hillsboro, OR, USA) was utilized to identify the crystalline structures of interfacial phases. Prior to TEM investigations, the thin foils were prepared by an ion beam milling technique.