iron(III) nitrate nonahydrate (>98%), scandium(III) nitrate hydrate
(99.9%), bismuth(III) nitrate pentahydrate (98%), NaOH (98%), and
1-hexanol were obtained from Alfa Aesar. Octadecylphosphonic acid
(OPA), (12-phosphono)dodecyl phosphonic acid (DPA), and HNO3 were purchased from Sigma-Aldrich. N,N,N,N-ethylenediaminetetra(methylenephosphonic
acid) hydrate (EDTMP hydrate) was obtained from abcr GmbH, (12-phosphono)dodecyl
sulfonic acid (PSA) from Sikemia, and toluene was obtained from VWR
Chemicals. All chemicals were used as received.
Sc-substituted
BHF nanoplatelets (BHF NPLs) were synthesized hydrothermally at 240
°C, as described previously,3 (link) starting
with a nominal molar ratio of metal nitrates (Fe + Sc)/Ba = 5 and
Fe/Sc = 9. Stable aqueous suspensions of the BHF NPLs were obtained
at pH = 2–2.2, which was adjusted with a 14.3 M solution of
HNO3. The chemical composition of the NPLs was determined
in average to be Ba1±0.08Fe14.9±0.12Sc0.87±0.10Ox, and their
thickness was found to be ca. 3–5 nm.16 (link) The width of the as-synthesized BHF NPLs was determined (see
electron microscopy (TEM) images (as in
fractions and coating densities (for details, see the
width of 50 or 60 nm (