Understanding surface photochemistry from first principles: The case of CO–TiO2(110)

Phys. Chem. Chem. Phys.

2014

Self Cite

Due to its high photocatalytic activity, TiO2 is of eminent interest for a manifold of applications ranging from surface catalysis up to solar energy conversion. However, the fundamental mechanisms of the underlying surface photochemistry are by no means understood. Focussing on this drawback, laser-induced photodesorption of CO on an ideal rutile TiO2(110) surface is studied using first principles in terms of a model system. This paper presents both quantum chemical as well as quantum dynamical results, taking into account the desorption coordinate Z, the polar angle θ, and the azimuth angle ϕ of the adsorbate. Detailed insight into the fundamental mechanisms of the photodesorption process in this model system is obtained, and a new desorption scenario is elucidated.

Section: Methodssupporting

confidence: 83%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Photoinduced desorption of CO from rutile TiO₂: elucidation of a new desorption mechanism using first principles

Spieker

Phys. Chem. Chem. Phys.

2014

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“…The basis set is of nearly triple zeta quality for the central atoms of the cluster and has been published elsewhere. 6,7 However, we have changed the basis set for the central oxygen atoms in the bridging oxygen rows because they bind to the dissociated hydrogen during the reaction. Therefore, their basis sets are chosen to be equivalent to the one of the water oxygen (see below).…”

Section: Methodsmentioning

confidence: 99%

Photodesorption of water from rutile(110): ab initio calculation of five-dimensional potential energy surfaces of ground and excited electronic states and wave packet studies

Mitschker

Phys. Chem. Chem. Phys.

2015

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In this paper, we report on our results concerning the interaction of water with titanium dioxide in its rutile modification. The (110) surface is modelled by an embedded Ti9O18Mg7(14+) cluster. We present up to five-dimensional potential energy surfaces for the water molecule on this surface and include the dissociation of one hydrogen atom. The electronic ground state as well as one electronically excited state is included. To deal with the multi-configurational character of the wave function, we use the complete active space self-consistent field (CASSCF) approach. The resulting potential energy surfaces are fitted by means of an artificial neural network. As a first example of quantum dynamical studies based on our potential surfaces, we present results on the photodesorption of water from rutile(110).

“…Future investigations should hence concentrate on systems with different substrates, e.g., titanium oxide. For the system CO/TiO 2 (110) exact ab initio potential energy surfaces for both the electronic ground and electronically excited states exist [57]. Since the crystal structure of TiO 2 (110) is much more complex than the crystal structure of NiO(100) a different model for the bath modes has to be derived.…”

Section: Discussionmentioning

confidence: 99%

A Surrogate Hamiltonian study of femtosecond photodesorption of CO from NiO(100)

Asplund

2013

Molecular Physics

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In this paper, the Surrogate Hamiltonian approach is employed in order to study electronic relaxation in femtosecond laserinduced desorption experiments of CO from NiO(100). The study is based on ab initio calculations and a microscopic description of the NiO(100)-surface and the relaxation mechanism developed by Koch et al. The relaxation mechanism is assumed to be of dipole-dipole interaction nature, where the transition dipole moment of the adsorbate interacts with surface electron-hole pairs. In the Surrogate Hamiltonian approach the electron-hole pairs are treated as two-level systems and are described by excitation energy and a dipole charge. The Surrogate Hamiltonian parameters and potential energy surfaces used are obtained from ab initio calculations. The desorption probability and the velocity distributions of the desorbing molecules are calculated and an excited state lifetime is predicted. Throughout this paper atomic units, i.e. = m e = e = a 0 = 1, have been used unless otherwise stated.