Highly efficient hydrogen production and formaldehyde degradation by Cu2O microcrystals.

Herein, Cu 2 O microcrystals are found to perform efficiently in hydrogen generation and formaldehyde degradation at room temperature, with MgO as a sacrificial agent, while other photocatalytic semiconductors such as TiO 2 , ZnO, Bi 2 O 3 , Fe 2 O 3 and CuO exhibit poor capability under the same condition. This peculiarity of Cu 2 O microcrystals is comprehensively analyzed, focusing on exploring the formation of [Cu + ]· paramagnetic during the reaction, which is first proposed as a principal factor for the hydrogen generation and formaldehyde degradation. Even more exciting, abundant hydroxyl radicals produced during this reaction process are detected via electron paramagnetic resonance spectrometry, which are particularly efficient in oxidizing formaldehyde and producing hydrogen. [ABSTRACT FROM AUTHOR]