Search

Graphyne (GYN) has received immense attention in gas adsorption applications due to its large surface area. The adsorption of toxic ammonia and nitrogen halides gaseous molecules on graphyne has been theoretically studied at ωB97XD/6–31 + G(d, p) level of DFT. The counterpoise corrected interaction energies of NH3, NF3, NCl3, and NBr3 molecules with GYN are − 4.73, − 2.27, − 5.22, and − 7.19 kcal mol−1, respectively. Symmetry-adapted perturbation theory (SAPT0) and noncovalent interaction index (NCI) reveal that the noncovalent interaction between analytes and GYN is dominated by dispersion forces. The significant change in electronic behavior, i.e., energies of HOMO and LUMO orbitals and NBO charge transfer correspond to the pronounced sensitivity of GYN towards considered analytes, especially NBr3. Finally, TD-DFT calculation reveals a decrease in electronic transition energies and shifting of adsorption to a longer wavelength. The recovery time for NX3@GYN is observed in nanoseconds, which is many orders of magnitude smaller than the reported systems. The recovery time is further decreased with increasing temperature, indicating that the GYN benefits from a short recovery time as a chemical sensor. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sensing capability of aminated graphdiyne (GDY-NH 2) towards common environmental pollutants by using DFT. • GDY-NH 2 forms energetically stable complexes with acetamide, thioacetamide, benzamide, and thiobenzamide. • Adsorption of the analytes decreases the HOMO-LUMO E gap. • The analytes interact with GDY-NH 2 via non-covalent van der Waals forces. • Stability, QTAIM, NCI, FMOs, NBO, and DOS analyses are executed to evaluate the applicability of the sensing. The detection of common environmental pollutants through chemical sensors has received significant interest from the scientific community. Acetamide (AM), benzamide (BM), thioacetamide (TAM), and thiobenzamide (TBM) are hazardous chemicals to humans and can cause many diseases including cancer, chronic liver damage, and acute skin irritations. Recently, functionalized 2D carbon-based materials have been used extensively as chemical sensors. Functionalization of these materials introduces adsorption sites which facilitates the interactions with the analytes. In this study, the sensing capability of the recently synthesized aminated graphdiyne material (GDY-NH 2) is explored towards AM, BM, TAM, and TBM via density functional theory (DFT) calculations. The results revealed that GDY-NH 2 forms stable complexes with the considered analytes. The interaction energies are −10.64, −11.92, −11.19, and −13.28 kcal/mol for AM@GDY-NH 2 , BM@GDY-NH 2 , TAM@GDY-NH 2 , and TBM@GDY-NH 2 , respectively. Quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analyses revealed that the interaction between GDY-NH 2 and the analytes occurs mainly via weak non-covalent van der Waals forces. A decrease in the HOMO-LUMO energy gap after interaction corresponds to a change in conductivity of the material. Furthermore, to ensure that the analytes are properly released after the detection, the turnover time has been theoretically calculated. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study theoretically presents the sensing affinities of cyclic tetrapyrrole (CTPy) towards toxic gaseous molecules. • The sensitivity of CTPy is measured against the toxic chemicals namely NH 3 , NF 3 , NCl 3 and NBr 3. • ωB97XD/6-31+G(d, p) level of DFT has implemented to measure the sensitivity of CTPy. • DFT results proved that CTPy is highly sensitive towards the considered analytes. Toxic gas sensors with ultrahigh sensitivity are highly desirable and those can be achieved with the help of infinite π-conjugation of cyclic conducting polymers. In this DFT study, we demonstrate the adsorption performance of tetracyclic oligopyrrole (CTPy) towards NH 3 and nitrogen halides including NF 3 , NCl 3 and NBr 3. The CTPy possesses infinite conjugation and highly active cavity which provides an excellent platform for the adsorption of upcoming gas molecules. Thermodynamically, the observed interaction energies of NH 3 , NF 3 , NCl 3 and NBr 3 analytes with CTPy at ωB97XD/6-31+G(d,p) level of theory are −13.14, −3.00, −6.00 and −7.50 kcal/mol, respectively. In addition, the molecular dynamic simulations are performed at GFN2-xTB method to confirm the stability of CTPy and respective complexes. The SAPT0 and NCI analyses reveal that dispersion forces play a significant role to stablize these complexes. Moreover, the electrostatic component also contributes in stabilizing the NH 3 @CTPy, NCl 3 @CTPy and NBr 3 @CTPy complexes. The variation in the electronic properties including HOMO-LUMO gaps of complexes along with the significant NBO charge transfer indicate the increasing conductivity of CTPy upon complexation with reported analytes. The prominent charge transfer on interaction might be due to the increasing π to π* transition, thus the λ max is shifted to longer wavelength in UV–vis spectra. [ABSTRACT FROM AUTHOR]