BTEX adsorption on TiO₂ anatase and rutile surfaces: DFT functionals

Area of Science:

• Materials Science
• Computational Chemistry
• Environmental Science

Background:

• Benzene, toluene, ethylbenzene, and xylenes (BTEX) are volatile hydrocarbons of environmental concern.
• Understanding BTEX adsorption on metal oxide surfaces is crucial for environmental remediation.
• Titanium dioxide (TiO2) is a widely studied material for surface interactions.

Purpose of the Study:

• To investigate the gas-phase adsorption of BTEX molecules on rutile (110) and anatase (101) TiO2 surfaces.
• To evaluate the role of dispersion forces in BTEX-TiO2 interactions using DFT.
• To elucidate the adsorption mechanisms and binding energies.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Plane wave DFT with dispersion corrections was used to model BTEX adsorption.
• Analysis of interaction energies and electronic structure (Density of States) was performed.

Main Results:

• All BTEX molecules exhibited a similar adsorption trend on both rutile and anatase surfaces.
• Dispersion terms significantly contributed to the interaction energy calculations.
• Aromatic π interactions were identified as the primary binding force for BTEX on TiO2.
• Hybridization between Ti 3d and C 2p states was observed for benzene adsorption.

Conclusions:

• DFT calculations with dispersion corrections accurately describe BTEX adsorption on TiO2.
• Effective adsorption occurs due to aromatic π interactions, with secondary influences from methyl groups in p-xylene.
• The study provides insights into the interaction of volatile organic compounds with TiO2 surfaces.