Physical Adsorption and Raman Spectra of Hydrazine Hydrate on the Graphene Surface

In
experimental studies, hydrazine hydrate is widely employed as
a reducing agent for the conversion of graphene oxide to graphene.
Herein, we conducted theoretical calculations using cluster models
to investigate the adsorption behavior of hydrazine hydrate on the
surface of graphene. The calculated adsorption energy reveals that
hydrazine hydrate can physically bind to the graphene surface. Our
findings indicate that two hydrogen bonds stabilize the hydrazine
hydrate molecule, while its adsorption onto the graphene surface is
primarily driven by van der Waals forces. By combining computational
simulations and experimental measurements, we thoroughly examined
the Raman spectra of both free and adsorbed hydrazine hydrates, which
enabled us to gain detailed insights into their molecular vibrations.
Notably, in the Raman spectra of free hydrazine hydrate, a strong
peak at around 3300 cm–1 corresponds to the NH2 vibration. Similarly, peaks near 3300 cm–1 were observed in the Raman spectra of graphene with adsorbed hydrazine
hydrate molecules. The results are expected to provide valuable references
for future experimental investigations involving hydrazine hydrate.