Development of a ReaxFF reactive force field for titanium dioxide/water systems

Area of Science:

• Computational materials science
• Chemical reaction modeling
• Surface chemistry

Background:

• Accurate modeling of reactions in the titanium-oxygen-hydrogen (Ti-O-H) system is crucial for understanding various chemical processes.
• Existing computational methods may have limitations in describing reactive events and material properties simultaneously.

Purpose of the Study:

• To develop and validate a new ReaxFF reactive force field for the Ti-O-H system.
• To accurately describe the energetics and reaction pathways involving titanium dioxide and water.

Main Methods:

• Parameterization of the ReaxFF force field using a comprehensive quantum mechanical (QM) training set.
• Inclusion of experimental data such as crystal structures and heats of formation for validation.
• Density Functional Theory (DFT) calculations were used for QM training set generation and validation via DFT/Molecular Dynamics (MD) simulations.

Main Results:

• The developed ReaxFF force field accurately reproduces QM training set data for structures and energetics of small clusters.
• ReaxFF successfully describes the relative energetics of different titanium dioxide polymorphs (rutile, brookite, anatase).
• ReaxFF simulations show good agreement with QM and DFT/MD results for water binding energies, surface energies, and H2O dissociation barriers on rutile (110).

Conclusions:

• The new ReaxFF force field provides a reliable and efficient tool for simulating reactions in the Ti-O-H system.
• The model demonstrates good predictive capability for water-titanium dioxide interactions, crucial for catalysis and surface science applications.