Computational Study of Interaction and Removal of Benzopyran by Anatase Titanium Dioxide Nanoparticle

Abstract

Most gas emissions by motor automobiles include unburned hydrocarbons, carbon monoxide, and other oxides (NxOy, SOx, etc.). There are many hydrocarbon compounds in car exhaust, such as benzopyran, formaldehyde, butadiene, and so on. In this study, anatase titanium dioxide nano-particles (aTiO2-NPs) filters are investigated to prevent the entry of unburned hydrocarbons. Benzopyran is one of the most important aromatic compounds in car exhaust gases, which is very dangerous. The probability of its interaction with titanium oxide nanoparticles is simulated and evaluated according to chemically active sites of aTiO2-NP. Calculations were performed using the DFT calculation on the basis set LC-ωPBE/6-311 + G** method. The obtained data show that Ti–O chemically active site has a greater tendency to adsorb benzopyran due to its polarity (Dipole moment for 3rd of Ti–O = 6.93 D). By adsorbing benzopyran in the Ti–O position, the gap energy of aTiO2-NP decreases (E g = 3.09 eV), and its conductivity increases. The results showed that the nano-adsorbent of aTiO2-NP has high efficiency in the adsorption of benzopyran from the environment. Due to the exhaust temperature of the car and the photocatalytic properties of the aTiO2-NPs nano-adsorbent, it can be used as an adsorbent with high performance and longevity, and good stability in high-temperature ranges.