Figure 2. (A) Schematic diagram of preparation process of
monolayer LDH nanosheets; (B) Schematic diagram of LDH modification by
TA; (C) FTIR spectra of LDH and TA@LDH; (D) Partial magnification of
FTIR spectra.
Single-layer LDH nanosheets rich in hydroxyl groups were obtained by
delaminating MgAl(NO3)-LDH in formamide (Figure 2A).
Then, the surface of the monolayer LDH nanosheets was modified by TA
(Figure 2B). Upon irradiation by a red laser, the LDH and TA@LDH
suspensions both show clear Tyndall effect, indicating their homogeneity
(Figure S3 A and B, Supporting information). The interaction between TA
and LDH was investigated by FTIR spectra (Figure 2C). The LDH and TA@LDH
both display obvious absorption peaks at 3500 cm−1 and
1642 cm−1, which are ascribed to stretching and
bending vibration absorption of O−H. For LDH sample, a strong sharp
absorption peak at 1384 cm−1 is attributed to the
antisymmetric stretching vibration of
NO3−. Bending vibration of M−O−M
appears at 837 cm−1, which shifts to 880
cm−1 after hybridization with TA. The blue shift of
M−O−M absorption band for the TA@LDH sample suggests the formation of
hydrogen bonds between TA and LDH.