Synthesis, Growth, and Characterization of Methyl Orange Dye-Doped Potassium Sulphate Single Crystal and Its Multifaceted Activities

Table 1

FTIR band assignment of methyl orange (MO) dye-doped K₂SO₄ single crystal.

MO dye	Pure K2SO4	MO doped K2SO4	Band assignment
3439	3439	–	Asymmetric and symmetric N-H stretching of the NH3 group, C–H stretching of the CH2 group, and O-H stretching of the hydrogen-bonded carboxyl group [21]
2921	2925	–	P-OH stretching vibrations [22]
–	–	2087	P-H stretching [22]
1606	1625	–	P-O stretching [21]
1365	–	–	Combination of asymmetric bending vibration of PO4 with the lattice [22]
1193, 1121	1103	1106	P-O bending vibration [21]
816	–	–	P-O-H bending vibration [22]
669, 570	–	–	PO4 bending vibration [23]
–	613	617	SO4^2- ion of the sulphate group [23]