spectra were recorded on a Perkin Elmer Spectrum 2 FT-IR instrument
(optical resolution of 0.5 cm–1) in attenuated total
reflectance (ATR) measurement mode (analyses in the 400–4000
cm–1 range, performed by averaging four acquisitions
per sample).
pXRD analyses were performed on an X’Pert
MPD diffractometer using Cu Kα1 radiation (λ
= 1.5406 Å) with the operating voltage and current maintained
at 40 kV and 25 mA, respectively. Diffractograms were recorded between
5 and 60° in 2θ, with a step size of 0.017° (with
a count time per step of ∼50 s).
SEM analyses were carried
out on a Zeiss Evo HD15 scanning electron
microscope equipped with an Oxford Instruments X-MaxN SDD 50 mm2 EDXS detector. Before the SEM analyses, samples were deposited
on a double-sided conducting carbon tape and then metallized with
carbon.