Nitrogenated holey graphene (C2N) surface as highly selective electrochemical sensor for ammonia

Abstract

Electron rich nitrogenated holey graphene C2N-h2D material with controlled pore size is explored as an efficient sensor and adsorption material for toxic and warfare agents (NH3, H2S, PH3, HCN and HF, NF3, NCl3, COCl2). The adsorption of all analytes on C2N surface is evaluated by using adsorption energy, non-covalent interactions, quantum theory of atoms in molecule, symmetry adopted perturbation theory, natural bond orbital (NBO), and frontier molecular orbital (FMOs) analysis. For studied analytes, adsorption energy ranges from −21.56 to −6.91 kcal/mol. SAPT0 analysis shows that electrostatic factor remains dominant in hydrogen containing analytes, while dispersion factor is dominant in halogen containing analytes. The SAPT0 results corroborate nicely with the results of adsorption energy expect for NF3. The least value of SAPT0 resulted due to enhanced repulsive part of NF3@C2N complex. The HOMO-LUMO energy gaps for PH3@C2N (3.42 eV), H2S@C2N (2.84 eV) and NH3@C2N (2.52 eV) are consistent with the results of interaction energy and SAPT0 analysis. FMO analysis reveals that a significant decrease in HOMO-LUMO energy gap is observed when charge is shifted from analytes to C2N surfaces. Among eight analytes efficient lowering of HOMO-LUMO energy gap (2.52 eV) is observed for NH3@C2N. Thus, C2N is a potential candidate for sensing and trapping of H2S and NH3 analytes.