Dxr raman spectrometer

The nanomaterials’
morphology was investigated by a field emission scanning electron
microscope (FE-SEM, Hitachi SU 6600, Japan). ImageJ was employed to
obtain the Au NP size distribution through a contrast filter. The
calculated diameter of the Au NPs (approximated as a circumference)
was retrieved thanks to the NP areas obtained by ImageJ. XPS analysis
was performed on a Nexsa G2 (Thermo Fisher Scientific) with an Al
Kα source (photon energy of 1486.7 eV; spot size of 100 μm).
The obtained data were evaluated by using Avantage software and CasaXPS.
High-resolution spectra were scaled using the adventitious carbon
peak as a reference. Raman spectra were collected using a DXR Raman
spectrometer (Thermo Scientific, Massachusetts) operating at 633 nm
and 4 mW. The PL spectroscopy measurements were performed on an FLS980
fluorescence spectrometer (Edinburgh Instruments) with double monochromators
on both excitation and emission sides, equipped with an R928P photomultiplier
in a thermoelectrically cooled housing (Hamamatsu Photonics), with
a 450 W xenon arc lamp as the excitation source. Spectral correction
curves were provided by Edinburgh Instruments.

The produced NPs were characterized using various characterization techniques to confirm the functionalization and to explore its effects on GO properties. XPS measurements were conducted over a 0–1200 eV range on a Kratos AXIS Ultra DLD (Kratos Analytical Ltd, Manchester, UK) with Al-Kα source and X-ray power of 15 Kv and 20 mA. The elemental compositions of GO and GO-PDA were analyzed using FLASH 2000 elemental analyzer (Thermo Scientific™, Waltham, MA, USA). XRD measurements were carried out using EMPYREAN PANalytical diffractometer (Malvern Panalytical B.V., Eindhoven, Netherlands) equipped with a Cu-Kα radiation source (λ = 1.5406 Å). FTIR-UATR spectra were determined using FTIR Perkin Elmer 2000 in the range of 400–4000 cm⁻¹ to study the surface functional groups of pristine GO and GO-PDA.
Raman spectra of the prepared NPs were obtained with DXR Raman Spectrometer operated with a 532 nm laser and a 10× objective (Thermo Scientific™). Moreover, the morphological structure of GO and GO-PDA NPs was investigated using SEM analysis that was conducted using the JEOL model JSM-6390LV. TGA analysis was conducted to assess the thermal stability of both samples using Pyris 6 TGA (PerkinElmer, Waltham, MA, USA) under nitrogen gas at a 10 °C/min heating rate and over a temperature range of 30–800 °C.

Raman spectra are taken with a Thermo Fisher DXR Raman spectrometer using a 455-nm laser source with a power of 1 mW and 20 s duration multiple exposures. Raman spectra and maps for encapsulated graphene were acquired in a Thermo Fisher DXRxi Raman spectrometer using a 455-nm source, with a power of 10 mW and 20 s duration to provide adequate signal to noise ratio from the graphene within the heterostructure.

Specific surface area of RGO paper or carbon paper cathodes was determined with the Brunauer–Emmett–Teller (BET) method as previously described^{53 (link)}. The Agilent 8453 G1103A spectrophotometer (Agilent, Denmark) was used to measure the UV-vis spectrum of the GO solution. X-ray photoelectron spectroscopy (XPS) was performed with a Thermo Scientific™ K-Alpha™ + X-ray Photoelectron Spectrometer System with an aluminum K-Alpha (1486 eV) as x-ray source. All the samples were deposited on polished Si-wafer by drop casting for XPS measurements. X-ray spot area for measurement was set at 400 μm and flood gun was used for charge compensation. Raman spectroscopy was conducted with a Thermo Scientific DXR Raman spectrometer equipped with a 455 nm laser.

The morphology and microstructure of the samples were observed using a Hitachi SU8010 field emission scanning electron microscopy (SEM). Pore textures of the prepared biochar samples were determined by N₂ adsorption–desorption isotherms at 77 K using an ASAP 2020 instrument. X-ray diffraction (XRD) patterns were performed on a Bruker D8 Advance diffractometer with Cu Kα radiation. Raman spectra were conducted on a laser confocal microscopy Raman spectrometer (DXR, Thermo Fisher, Waltham, MA, USA) at 532 nm. X-ray photoelectron spectroscopy (XPS) was recorded on a Multilab 2000 with Al Kα radiation for surface chemical species detection.

The structural information of the obtained samples was characterized by using a powder X-ray diffractometer (XRD, Rigaku) equipped with a Cu-Kα radiation of 0.15418 nm, and Raman spectra were recorded by using Raman spectrometer (DXR, Thermo-Fisher Scientific). N₂ absorption/desorption isotherms were collected by Micromeritics ASAP 2020 instrument, and the pore size distributions of samples were calculated by non-local density functional theory (NLDFT) method. Moreover, an X-ray photoelectron spectroscopy (XPS, VG Multi Lab 2000 system) was carried out for analyzing the compositions of the products. The surface morphology and inner structure were detected by scanning electron microscopy (SEM, Hitachi S-4800) and high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM, Titan G2 60-300). Electronic conductivity is reciprocal of electronic resistivity, and electronic resistivity of carbon membrane was carried out at room temperature under 0.55 T magnetic field using the van der Pauw method by the Hall measurement (ECOPIA HMS 3000). Moreover, the carbon membrane was prepared with grinding apparatus by using the powder compressing machine under the 10 MPa.