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spectra of these materials [82–84]. Along with THz-TDS, time-resolved terahertz
spectroscopy (TRTS) has also been utilized to measure the photoconductivity of
MOFs accurately [85].
Phase transitions in molecular crystals can also be explored using THz-TDS.
Generally, phase transitions in molecular crystals occur via a nucleation and growth
mechanism. However, in DL-norvaline, this mechanism is Martensitic, where
the lattice does not undergo random reorganization but shows a memory effect.
Temperature-dependent THz spectroscopy of DL- norvaline shows a remarkable
change in the absorption spectra at low temperatures, suggesting a phase transition.
More information on the dynamics of this transition is obtained by changing the
grain size and doping the crystal with similar amino acids [86] (Fig. 11).
Water solvation of gold nanoparticles has also been probed using THz spectroscopy. Gold nanoparticles have been used as electrocatalysts for oxygen reduction, carbon dioxide reduction, and alcohol oxidation. Mid IR (MIR) and THz spectroscopy have been used to explore the entire range of intramolecular and intermolecular dynamics of liquid water in the presence of charged and neutral gold
nanoparticles [87]. A large number of aqueous salt solutions have also been studied
using THz-TDS. In a recent study utilizing THz-FTIR spectroscopy, the resonances
for anions have been identified as the rattling motion of the ions inside their hydration
Fig. 11 The measured absorption coefficient of DL-norvaline. The absorption spectrum changes
dramatically between 190 and 180 K, indicating that the crystal lattice changes at this temperature.
The absorption increases with decreasing temperature and reaches a maximum at 140 K. The
absorption then decreases as the temperature is further decreased. Adapted with permission from
Ref. [86]. Copyright 2018 American Chemical Society
S. Banerjee et al.
spectra of these materials [82–84]. Along with THz-TDS, time-resolved terahertz
spectroscopy (TRTS) has also been utilized to measure the photoconductivity of
MOFs accurately [85].
Phase transitions in molecular crystals can also be explored using THz-TDS.
Generally, phase transitions in molecular crystals occur via a nucleation and growth
mechanism. However, in DL-norvaline, this mechanism is Martensitic, where
the lattice does not undergo random reorganization but shows a memory effect.
Temperature-dependent THz spectroscopy of DL- norvaline shows a remarkable
change in the absorption spectra at low temperatures, suggesting a phase transition.
More information on the dynamics of this transition is obtained by changing the
grain size and doping the crystal with similar amino acids [86] (Fig. 11).
Water solvation of gold nanoparticles has also been probed using THz spectroscopy. Gold nanoparticles have been used as electrocatalysts for oxygen reduction, carbon dioxide reduction, and alcohol oxidation. Mid IR (MIR) and THz spectroscopy have been used to explore the entire range of intramolecular and intermolecular dynamics of liquid water in the presence of charged and neutral gold
nanoparticles [87]. A large number of aqueous salt solutions have also been studied
using THz-TDS. In a recent study utilizing THz-FTIR spectroscopy, the resonances
for anions have been identified as the rattling motion of the ions inside their hydration
Fig. 11 The measured absorption coefficient of DL-norvaline. The absorption spectrum changes
dramatically between 190 and 180 K, indicating that the crystal lattice changes at this temperature.
The absorption increases with decreasing temperature and reaches a maximum at 140 K. The
absorption then decreases as the temperature is further decreased. Adapted with permission from
Ref. [86]. Copyright 2018 American Chemical Society