Tensor 2 spectrometer

An X-ray diffractometer (Panalytical X’Pert Pro, Almelo, The Netherlands) using copper/Kα radiation (λ = 1.5418 Å) captured XRD patterns. A Tensor II spectrometer (Bruker, Denkendorf, Baden-Württemberg, Germany) was utilized to record the FT-IR spectra. A scanning electron microscope (MIRA3, Tescan, Brno, Czech Republic) provided the FE-SEM images and the EDX patterns. An autolab potentiostat/galvanostat (PGSTAT-302N, Eco Chemie, Utrecht, The Netherlands) recorded all electrochemical determinations. The General Purpose Electrochemical System (GPES) as selected software monitored all testing protocols. A conventional three-electrode system was used at 25 ± 1 °C. An Ag/AgCl/KCl (3.0 M) electrode, a platinum wire and MnO₂NR-IL/CPE were used as the reference, auxiliary and working electrodes, respectively. A pH meter (Metrohm type 713) was utilized to determine all solution pH values. All solutions were prepared freshly by deionized water (DIW, Millipore Direct-Q^® 8 UV water purification system, Darmstadt, Germany). Sulfanilamide, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF₆) ionic liquid, and all materials were purchased from Merck (Darmstadt, Germany) with analytical research purity. Orthophosphoric acid as well as relevant salts have been applied to achieve all phosphate buffer solutions (PBS), set in a pH range of 2.0–9.0.

All manipulations were conducted under a nitrogen atmosphere using standard Schlenk techniques. All reagents were purchased from commercial vendors: benzamidine (L^NN-H) (Sigma-Aldrich), ZnEt₂ (ABCR). Solvents were purified and dried using MBraun Solvent Purification System (SPS). The ¹H and ¹³C NMR spectra were acquired on Varian Mercury (400 MHz) spectrometer. FTIR spectra were recorded on a Bruker-Tensor II spectrometer. Powder X-ray diffraction (PXRD) measurements were performed using a PANalytical Empyrean diffractometer equipped with Ni-filtered Cu Kα radiation (40 kV, 40 mA). The sample for the PXRD analysis was sealed between two layers of Kapton foil and measured in transmission geometry. Elemental analyses were performed on an Elementar VarioMicro Cube analyzer. TGA-differential scanning calorimetry (DSC) analyses were performed under argon with a heating rate of 5 °C min⁻¹ using a TA Instruments Q600 apparatus. Volumetric N₂ sorption studies were undertaken using a Micromeritics ASAP 2020 system. Approximately 150 mg of 1^LT and dried under vacuum at −10 °C for 5 h. Helium was used for the free space determination after sorption analysis. Adsorption isotherms were measured at 77 K in liquid nitrogen.

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.

FTIR spectra were obtained using a Bruker Tensor II spectrometer (Bruker, Karlsruhe, Germany). Scanning electron microscopy (Hitachi S4800, Hitachi, Tokyo, Japan) and TEM (Lorentz JEM-2100, JEOL, Tokyo, Japan) were used for microstructural characterization. Particle size, zeta potential, and PDI were calculated at 25 °C using a Malvern ZS90 laser particle size analyzer (Malvern, Worcestershire, UK). The average diameter, pore size, and specific surface area under nitrogen adsorption–desorption conditions were determined using a Quadrasorb EVO gas adsorption apparatus (Quanta Instruments, Boynton Beach, FL, USA), based on the Brunauer-Emmett-Teller (BET) equation. The elemental content was quantified using energy-dispersive X-ray spectroscopy (EDS) and the phases of the as-synthesized nanoparticles were analyzed using XRD (D8 Advance, Bruker, Karlsruhe, Germany). The elemental compositions and chemical states of the materials were analyzed via XPS (ESCALAB, Thermo Fisher Scientific, Waltham, MA, USA).

The FTIR spectra of GEP and its derivatives were acquired using a TENSOR II spectrometer (Bruker Corporation, Ettlingen, Germany) in the wavenumber range of 400–4000 cm⁻¹. The sample was mixed with KBr to a ratio of approximately 1:100 (w/w). The mixture was ground to a homogenous powder and then pressed into tablets. The FTIR spectra of the samples were recorded with a resolution of 4 cm⁻¹ and 32 scans.