Detection of Carbon, Sulfur, and Nitrogen Dioxide Pollutants with a 2D Ca₁₂O₁₂ Nanostructured Material

Abstract

In recent times, nanomaterials have been applied for the detection and sensing of toxic gases in the environment owing to their large surface-to-volume ratio and efficiency. CO 2 is a toxic gas that is associated with causing global warming, while SO 2 and NO 2 are also characterized as nonbenign gases in the sense that when inhaled, they increase the rate of respiratory infections. Therefore, there is an explicit reason to develop efficient nanosensors for monitoring and sensing of these gases in the environment. Herein, we performed quantum chemical simulation on a Ca 12 O 12 nanocage as an efficient nanosensor for sensing and monitoring of these gases (CO 2 , SO 2 , NO 2 ) by employing high-level density functional theory modeling at the B3LYP-GD3(BJ)/6-311+G(d,p) level of theory. The results obtained from our studies revealed that the adsorption of CO 2 and SO 2 on the Ca 12 O 12 nanocage with adsorption energies of −2.01 and −5.85 eV, respectively, is chemisorption in nature, while that of NO 2 possessing an adsorption energy of −0.69 eV is related to physisorption. Moreover, frontier molecular orbital (FMO), global reactivity descriptors, and noncovalent interaction (NCI) analysis revealed that the adsorption of CO 2 and SO 2 on the Ca 12 O 12 nanocage is stable adsorption, while that of NO 2 is unstable adsorption. Thus, we can infer that the Ca 12 O 12 nanocage is more efficient as a nanosensor in sensing CO 2 and SO 2 gases than in sensing NO 2 gas.

B- and Al-Doped Porous 2D Covalent Organic Frameworks as Nanocarriers for Biguanides and Metformin Drugs

“…The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are commonly described as frontier molecular orbitals (FMOs) and their energies are central to investigating the stability and chemical reactivity of molecular substances . Energy gap, which is the difference between the HOMO and LUMO energies, is also essential in charge transfer and sensing tendency in a scheme . The energy gaps values for molecules that are very reactive and less stable are small, while the reverse is true for compounds that are less reactive and stable.…”

“…38 Energy gap, which is the difference between the HOMO and LUMO energies, is also essential in charge transfer and sensing tendency in a scheme. 39 The energy gaps values for molecules that are very reactive and less stable are small, while the reverse is true for compounds that are less reactive and stable. The HOMO−LUMO energy gaps of the investigated COF surfaces and their complexes were computed employing ωB97XD/6-311++G (d,p) level of theory as shown in Table 3, and distribution patterns of their frontier molecular orbitals are displayed in Figure 5, respectively.…”

Computational design and molecular modeling of the interaction of nicotinic acid hydrazide nickel-based complexes with H2S gas

“…The blue region with negative values, l 2 (r)r(r) < 0 corresponds to strong interactions (such as hydrogen bonding) and high electron density, while the red region with positive values (l 2 (r)r(r) > 0) indicates a strong repulsive interaction (like steric effect) and electron density depletion; the green region (sign l 2 (r)r(r) z 0) corresponds to relatively weak van der Waal interactions. 56,57 As evident from the plots in Fig. 6, the blue regions existing between H 2 S and the complexes indicate the presence of strong hydrogen-bonding interactions.…”

Toward Site-Specific Interactions of nH2 (n = 1–4) with Ga12As12 Nanostructured for Hydrogen Storage Applications

“…In this section, in line with previous studies that examined the H 2 adsorption on the surface of pure or modified nanocages, we will examine the adsorption of the H 2 (n = 1−4) molecules on the pristine Ga 12 As 12 ; the capacity of the Ga 12 As 12 nanocage to store hydrogen molecules and the best sites for the storage of hydrogen molecules between Ga and As atoms is analyzed. 57 Also, a comparison with previous studies will be carried out.…”