Nicolet 370 ft ir spectrometer

All materials of commercial reagent grade were purchased from the Merck and Aldrich companies and used without further purification. FT-IR spectra were recorded on a Nicolet 370 FT/IR spectrometer (Thermo Nicolet, USA) using pressed KBr pellets. X-ray diffraction (XRD) measurements were carried out with a Philips powder diffractometer type PW 1373 goniometer. It was equipped with a graphite monochromator crystal. The X-ray wavelength was 1.5405 Å and the diffraction patterns were recorded in the 2θ range (10–80) with a scanning speed of 2° min⁻¹. TEM images were taken using a Philips EM208 transmission electron microscope with an accelerating voltage of 90 kV. Scanning electron microscopy (SEM) of the {Fe₃O₄@SiO₂@(CH₂)₃5-phenyl-1H-tetrazole-SO₃H/HCl} was performed on a Cam scan MV2300. The chemical compositions of the synthesized catalyst were determined by EDS (energy dispersive X-ray spectroscopy) performed in SEM. Thermal analysis (TG-DTG) was carried out using an STA 1500 Rheometric Scientific (England). The flow rate of air was 120 mL min⁻¹ and the ramping rate of the sample was 2 °C min⁻¹. VSM measurements were recorded using a SQUID magnetometer at 298 K (Quantum Design MPMS XL). Melting points were taken in open capillaries using BUCHI 510 melting point apparatus and are uncorrected.