Adsorption behavior of explosive molecules on g-C3N4 nanostructure: A novel approach for sensing energetic materials

Inspired by the latest achievements of two-dimensional (2D) materials as gas sensors, we have performed abinitio calculations to simulate the interactions between the explosive molecules (RDX, TEX, FOX-7 and TATB) and g-C3N4 surfaces in order to exploit the potential applicability of g-C3N4 as explosive sensor. The adsorption energies and measured distances of g-C3N4/explosive configurations indicate that the TATB molecule interacts strongly with g-C3N4 and produces more number of extra peaks within the Fermi level region. The calculated sensitivity (S) test also demonstrates the superior sensitivity of g-C3N4 towards TATB molecule. Keeping other semiconducting materials like graphene and boron nitride in perspective, our calculations show higher binding energies when explosive molecules are adsorbed on g-C3N4 with appropriate charge transfer, representing better sensitivity for the latter. An increased work function is obtained when planar TATB and FOX-7 molecules are placed on the g-C(3)N(4 )surface. Further, the sensitivity of g-C3N4 for these explosive molecules is interpreted in terms of electronic and optical properties, where the density of states and absorption spectra show marked variations when explosive molecules are adsorbed on g-C3N4 surface. The significant overlap between the interacting atoms of adsorbate and adsorbent in PDOS spectra represents the formation of chemical bonds at the interface region. Our calculations demonstrate the adsorption and reactivity processes that occur at the interface region, being useful to develop and design devices with extreme sensitivity for explosive detection.