Tii confocal raman spectrometer

The morphological investigation of AgNPs, reduced graphene oxide (rGO), Gr-Ag (3, 5 and 20 wt% Ag) hybrids, and HEPA filter modified with Gr-Ag (5 wt% Ag) was conducted using the TEM/STEM Hitachi HD-2700 cold-field emission, operated at 200 kV (Hitachi, Tokyo, Japan). The structural characteristics of Gr-Ag (5 wt% Ag) hybrid material were studied by X-ray powder diffraction (XRD). The pattern was recorded with DIFFRAC plus XRD Commander Package on a Bruker-D8 Advance Diffractometer with the tube set at 40 kV and 40 mA. A germanium (1 1 1) monochromator was placed in the incident beam (λ = 1.54056 Å) and the scan rate was 0.02 s⁻¹. Raman spectroscopy was performed on Gr-Ag (5 wt% Ag) hybrid material using an NTEGRA Spectra platform, placed on a NEWPORT RS4000 optical table with a vibration isolation system and equipped with a SOLAR TII confocal Raman spectrometer coupled with an Olympus IX71 microscope in two different configurations. Detection was achieved with a CCD camera (NT-MDT; Moscow, Russia). FTIR measurements (4000–400 cm⁻¹) were recorded with a Bruker Tensor II spectrometer (Esslingen, Germany), with the Gr-Ag (5 wt% Ag) hybrid material embedded in KBr pellet.

In order to reveal the morphological characteristics of the graphene sample, we employed a Hitachi HD2700 instrument (Hitachi, Tokyo, Japan) equipped with a cold field emission gun (CSEG). The structural characterization of graphene was performed by X-ray powder diffraction (XRD). A Bruker D8 Advance Diffractometer (40 kV, 0.5 mA) equipped with an LYNXEXE detector (λ = 1.5406 Å) was employed. Raman spectra were recorded with an NTEGRA Spectra platform, which was placed on a NEWPORT RS4000 optical table and equipped with a SOLAR TII confocal Raman spectrometer coupled with an Olympus IX71 microscope in two different configurations (Moscow, Russia). The sample obtained after the electrochemical exfoliation of graphite rods was freeze-dried with Christ-Alpha 1-4 LSC equipment (Germany). All the electrochemical measurements (Cyclic Voltammetry—CV; Square Wave Voltammetry—SW, Amperometry—AMP and Electrochemical Impedance Spectroscopy—EIS) were recorded with a Potentiostat/Galvanostat Instrument (PGSTAT-302N, Metrohm-Autolab B.V., Utrecht, The Netherlands).