4.3. Characterization

The morphology and size of the synthesized nanoparticles were observed by a SEM-Field Emission Scanning Electron Microscope (FEG-SEM)-Nova NanoSEM 630. The characterization was performed at magnifications of 120 kx, 100 kx, and 60 kx, and at acceleration voltages of 10 kV and 15 kV using the In-lens Secondary Electrons detector (TLD-SE). EDX mapping was fulfilled through SEM-EDX analysis performed with the aid of a Zeiss Gemini 500 microscope coupled with an XFlash 6 EDX detector from Bruker. All data from the EDX were analyzed using the ESPRIT 2 Software. Raman measurements were performed at room temperature with a Horiba micro-Raman spectrometer LabRAM HR 800, heliu-Neon Laser, which was 633 nm with a confocal Olympus microscope. A 100× objectiv was used to focus on ZnO nanoparticles’ powder and Raman-scattered light was collected through the same microscope objective and detected by a cooled CCD detector. For TiO₂ nanoparticles, the excitation source was a red laser (λ = 633 nm) with an output power of 15 mW and it was focused to a spot of ~ 0.8 µm. Before measurement, the system was calibrated using the 521 cm-1 Raman line of a silicon (Si) wafer. Raman spectra for zeolite was collected with the powder placed on an Au/glass substrate in order to enhance Raman-scattered light. The light source was a He-Ne laser (632.8 nm), with the laser spot at < 1 µm and ×100 objective of the Olympus confocal microscope. X-ray diffraction investigations were performed using a 9 kW SmartLab diffractometer (Osaka, Japan) operated at 40 kW and 75 mA. Powder XRD (PXRD) patterns were recorded using a step of 0.01° with a speed of 5°/min in the θ/2θ configuration. Gas chromatography mass spectrometry analyses were performed on a GC Focus-MS DSQII, Thermo Electron Corporation (Waltham, United States). GC analyses were performed on a TR5MS capillary column, with the dimensions of 30 m × 0.25 mm × 0.25 μm, using ultra-pure Helium (6.0), a 1 mL/min constant flow, constant pressure, the spitless injection mode (15 mL/min), and an injection volume of 1 μL. The GC temperature program consisted of 60 °C (2 min) with a heating rate of 10 °C to 300 °C (10 min). MS analyses were performed under the electron impact (EI) ionization mode at 70 eV electron energy, with a 3 min solvent dela, on a scan range of 40–650 m/z. The extreme temperature cycles were performed into an Angelantoni Industrie SpA climatic chamber, specifically the DY110 model (Cimacolle, Italy).