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(September 30, 2015) LMU
chemists have developed novel porous materials called “covalent organic
frameworks”, which provide a basis for the design of polymeric photocatalysts
with tunable physical, chemical and electronic properties.
Chemical systems that are capable of generating hydrogen gas
by light-activated scission of water molecules (often termed artificial
photosynthesis) represent a promising technology for the efficient storage of
solar energy. However, the systems that have been developed so far suffer from
various drawbacks, and intensive efforts are underway to discover alternative
procedures that are both more practical and efficacious. Chemists led by
Professor Bettina Lotsch, who has dual appointments in the Department of
Chemistry at LMU and the Max Planck Institute for Solid State Research in
Stuttgart now introduce a new class of porous organic materials that can be
used as the basis for molecularly tunable photocatalysts for light-driven
production of hydrogen gas. The researchers report their findings in the new
issue of the online journal Nature Communications.
Lotsch and her colleagues are interested in the properties
and practical applications of so-called covalent organic frameworks. These
materials are composed of layers of regular two-dimensional molecular networks
synthesized from simple organic precursors, and they exhibit a number of
features that facilitate photocatalytic processes. “They form crystalline and
porous semiconductors, whose chemical properties can be precisely tuned for a
given application,” as Bettina Lotsch explains. They are already under
investigation as possible matrices for the storage of gases and for
applications in sensor technology, and also have considerable potential in the
field of optoelectronics.