In this report, the structural, morphological and electro-optical analysis of 2-D graphitic carbon nitride (g-C3N4) nano-sheets has been performed. The g-C3N4 nano-sheets were synthesized based on the thermal calcination process and characterized by transmission electron microscopy (TEM). X-ray diffraction studies (XRD) showed the inter-layer spacing to be 0.323 nm for the (002) plane which is 3.5% more dense than crystalline graphite and higher than literature reports for g-C3N4. For the evaluation of electro-optical properties, we have utilized time-domain spectroscopy for the frequency range 0.2 to 2 THz. The complex reflective indices (n, k) and permittivity (ϵ,ϵ′) for g-C3N4 have been determined. The complex conductivity has been observed to increase monotonically with an increase in frequency. The mobility of g-C3N4 has been theoretically estimated. The terahertz band properties such as plasma frequency, damping rate (0.095 THz), and collision time, were calculated for the synthesized material. The high permittivity value for g-C3N4 as reported in this work is promising for THz frequency selective components such as resonators, absorbers and collimators.