Uv 2450 ultraviolet visible spectrophotometer

TEM observations were performed with a JEOL JEM-2100 microscope operated at 200 kV (C_s 0.5 mm, point resolution 1.9 Å). High-angle annular dark-field scanning STEM was performed on a JEOL JEM-2100F microscope equipped with STEM and EDS detectors for elemental mapping analysis. TEM and STEM samples were prepared by casting a suspension of the samples on a carbon coated copper grid (300 mesh). XRD patterns were recorded on powder samples using a D/max 2500 VL/PC diffractometer (Japan) equipped with graphite-monochromatized Cu Kα radiation. XPS was performed on a scanning X-ray microprobe (Thermo ESCALAB 250Xi) that uses Al Kα radiation. The binding energy of the C 1s peak (284.8 eV) was employed as a standard to calibrate the binding energies of other elements. UV-vis absorption spectroscopy was performed on a Shimadzu UV-2450 ultraviolet-visible spectrophotometer. FT-IR spectroscopy was performed on a Bruker Hyperion 2000. ¹H NMR spectra were recorded on an Avance III HD 400 spectrometer (400 MHz), and the chemical shifts were reported in ppm relative to the residual deuterated solvent and the internal standard tetramethylsilane.