Exploring photocatalytic processes at the atomic scale

Limitations in the supply and environmental hazards related to fossil-fuels have stimulated intense re-search activities on renewable energies. A particularly interesting approach in this respect is the solar energy conversion into electrical or chemical energy, the latter being compatible with natural photosynthesis. In the technical analogue, natural light is exploited to split water into stoichiometric amounts of hydrogen and oxygen, a process that takes place on the surface of a suitable photocatalyst. Alternatively, more complex chemical reactions might be induced by the optical excitation, e.g. the dissociation or structural rearrangement of larger organic complexes. In both cases, the underlying mechanism is based on the generation of hot carriers by exciting an electron from the valence to the conduction band of a dielectric matrix with typically 1-3 eV band gap. The hot carriers then evolve towards molecular species bound to the surface, where they produce a local excitation that either leads to a chemical activation, a conforma-tional change or a dissociation. Beyond this simplified picture, the fundamental processes involving a photochemical reaction are hardly understood, in particular when it comes to an atomic-scale description. Moreover, numerous ways on how to enhance the photochemical response of a system are discussed in the literature, for instance by introducing sensitizers or dopants. However, a conclusive picture of the under-lying processes only starts emerging in this field. In our project, we will use atomic-scale microscopic and spectroscopic techniques, in order to add to the understanding of light-driven reaction mechanisms and to facilitate the rational design of photocatalysts.

People and Collaborations

Caio Bosco, caiofbs1997 at gmail.com

Israel Fidelis,  israel.fidelis.fx at gmail.com

M.Sc Christian Stiehler

Dr. Marta Duarte, marta.d.fonseca at gmail.com

Prof. Martin Schmal, Universidade Federal do Rio de Janeiro

Prof. Niklas Nilius, Carl von Ossietzky Universität Oldenburg

Prof. Hans-Joachim Freund, Fritz-Haber-Institut der Max-Planck-Gesellschaft

Funding

FAPERJ, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro

CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico

Alexander von Humboldt Foundation

Max-Planck Society

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One Response to Exploring photocatalytic processes at the atomic scale

  1. Pingback: Oportunidades | Surface and Interface Phenomena Group at the Brazilian Center for Physics Research

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