September 30, 2015

Hydrogen for all seasons

Foto: Smileus /

(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.

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