ATOMISTIC SIMULATION OF DISSIPATIVE CHARGE CARRIER DYNAMICS FOR PHOTOCATALYSIS

Abstract

ABSTRACTPhoto-excitation of high surface area semiconductor nanorods decorated with surface catalyst particles are investigated. DFT-based simulation is applied to the charge transfer dynamics at the interface of the supported nanocatalyst by modeling dynamics of photo-excitations. The modeling is performed by reduced density matrix method in the basis of Kohn-Sham orbitals. The energy of photo-excitation is dissipating due to interaction with lattice vibrations, treated through non-adiabatic coupling as the electron/hole pair relaxes to the conduction / valence band edges. The methodology is applied to TiO2 nanorod modeled as a periodic anatase (100) slab functionalized by minimalistic nano-clusters or doping. Simulations of these models demonstrate the formation of charge transfer state in both time and frequency domain. Computed charge dynamics leads to creation of positively charged areas on the nanorod surface that is an important prerequisite for oxidation catalysis. Our computation identifies optimal composition and morphology of nanocatalyst for such applications as water splitting for hydrogen production or solar cells.