Sensing Potential of Carbon Nitride (C6N8) for the Detection of Hydrogen Sulfide (H2S) and Nitrogen Trichloride (NCl3): A DFT Approach

Carbon nitride (
$\text{C}_{{6}}\text{N}_{{8}}{)}$
is a unique 2-D porous material with remarkable electronic and chemical properties. In this study, we explored the sensitivity and selectivity of the
$\text{C}_{{6}}\text{N}_{{8}}$
surface for detecting hydrogen sulfide (
$\text{H}_{{2}}\text{S}$
) and nitrogen trichloride (NCl
$_{{3}}{)}$
gases via density functional theory (DFT) calculations. The interaction energy of complexes is −22.97 kJ/mol (
$\text{H}_{{2}}\text{S}$
at
$\text{C}_{{6}}\text{N}_{{8}}{)}$
and −17.79 kJ/mol (NCl3 at
$\text{C}_{{6}}\text{N}_{{8}}{)}$
with a noticeable difference in their bandgap (
${E}_{\text {gap}}{)}$
indicating the promising adsorption strength of the surface for the
$\text{H}_{{2}}\text{S}$
and NCl3 gases. The results of the quantum theory of atoms in molecule (QTAIM) analysis showed the presence of covalent and noncovalent interactions (NCIs) in the complexes. The partial density of state (PDOS) maps showed the energy states below the fermi level for
$\text{H}_{{2}}\text{S}$
and NCl3, demonstrating the sensitivity of these harmful gases for
$\text{C}_{{6}}\text{N}_{{8}}$
. The complexes have a little recovery time (
$9.969\times 10^{-{9}}$
s–
$1.249\times 10^{-{9}}$
s) at 300 K, suggesting that the
$\text{C}_{{6}}\text{N}_{{8}}$
surface can be used as a sensing material for
$\text{H}_{{2}}$
S and NCl3 analytes. Moreover, the results of the symmetry adapted perturbation theory (SAPT0) analysis (from −28.025 to −23.052 kJ/mol) indicated the stabilization of
$\text{H}_{{2}}\text{S}$
at
$\text{C}_{{6}}\text{N}_{{8}}$
and NCl3 at
$\text{C}_{{6}}\text{N}_{{8}}$
complexes. This study will promote the use of the
$\text{C}_{{6}}\text{N}_{{8}}$
surface in sensing applications for detecting toxic gases, especially NCl3 and
$\text{H}_{{2}}\text{S}$
.