Interaction of sulfur trioxide molecules with armchair and zigzag stanene-based nanotubes: electronic properties exploration by DFT calculations

Assessing the gas sensing capability of undoped and doped aluminum nitride nanotubes

CONTEXT

CO2 and CO gas sensors are very important to recognize the insulation situation of electrical tools. ToCO explore the application of noble metal doped of aluminum nitride nanotubes for gas sensors, DFT computations according to the first principal theory were applied to study sensitivity, adsorption attributes, and electronic manner. In this investigation, platinum-doped aluminum nitride nanotubes were offered for the first time to analyze the adsorption towards CO2 and CO gases. Firm construction of platinum-doped aluminum nitride nanotubes (Pt-AlNNT) was investigated in four feasible places, and the binding energy of firm construction is 1.314 eV. Respectively, the adsorption energy between the CO2 and Pt-AlNNT systems was - 2.107 eV, while for instance of CO, the adsorption energy was - 3.258 eV. The mentioned analysis and computations are considerable for studying Pt-AlNNT as a new CO2 and CO gas sensor for electrical tools insulation. The current study revealed that the Pt-AlNNT possesses high selectivity and sensitivity towards CO2 and CO.

METHODS

In this research, Pt-doped AlNNT (Pt-AlNNT) has been studied as sensing materials of CO and CO2 for the first time. The adsorption process of Pt-AlNNT has been computed and analyzed through the DFT approach. DFT computations by using B3LYP functional and 6-31 + G* basis sets have been applied in the GAMESS code for sensing attributes, which contribute to potential applications.

The adsorption of NO2, SO2, and O3 molecules on the Al-doped stanene nanotube: a DFT study

Adsorption of pollutant gas molecules (NO₂, SO₂, and O₃) on the surface of the Al-doped stanene nanotube was investigated within the first principle calculations of density functional theory (DFT). Adsorption mechanisms were studied by analyzing optimized structures, band structures, projected density of states (PDOS), charge density difference (CDD), molecular orbitals, and band theory. Investigation of charge transfer by Mulliken population showed that NO₂ accumulated while SO₂ and O₃ depleted charge density on the Al-doped nanotube. The differences in band structures before and after adsorption implied that the electronic characteristics of Al-doped nanotube changed dramatically in case of NO₂ adsorption, which converted Al-doped nanotube to a semiconductor material. High adsorption energy and the significant overlap between PDOS spectra indicated that the adsorption process was chemisorption for NO₂, SO₂, and O₃ on the doped nanotube with the obtained order of O₃ > SO₂ > NO₂. The results showed that the adsorption of NO₂, SO₂, and O₃ occurred on the Al-doped stanene nanotube, and that all the three gas molecules could be detected by Al-doped stanene nanotube with various detection strengths.

A new insight into SO2 low-temperature catalytic oxidation in porous carbon materials: non-dissociated O2 molecule as oxidant

O₂ can be activated at the carbon atom near basic oxygen-containing groups, generating C–O–O structure. The generated C–O–O structure can directly oxidize gaseous SO₂ to SO₃.