Phographene as a new carbon allotrope for adsorption and detection of SO2, AsH3, NO2, CF3H, and CO2 air pollutant gaseous species

Context

Phographene and its family member structures are of the newly proposed semiconductors for detection of chemicals. That is, in this project, the potential of using α-phographene (α-POG) both for adsorption and detection of five types of the most important air pollutant gases containing SO₂, AsH₃, CF₃H, NO₂, and CO₂ species were investigated.  The results of the time dependent density functional theory (TD-DFT) calculations indicate that during the adsorption of NO₂, and SO₂ by the sorbent, big redshifts occur (up to 866.2 nm, and 936.5, respectively) resulting in considerable changes in the orbitals and the electronic structures of the systems. Moreover, the results of the thermodynamic calculations reveal that α-POG could selectively adsorb SO₂, NO₂, and AsH3 gases (with different orders), but it could not adsorb the two other gases.Finally, the outcome of the band gap calculations shows that between all mentioned gases, α-POG could selectively detect the presence of SO₂, and then NO₂; while, this nanosheet could not sense the existence of AsH₃, CF₃H, or CO₂ gases.

Methods

All of the calculations were carried out by using the Gaussian 03 quantum chemical package. In addition, the physiochemical parameters were extracted from the output files for further calculations. Studies on all saddle points and the following calculations were performed applying the B3LYP/6-311g(d,p) level of theory.