Robust Photogeneration of H2 in Water Using Semiconductor Nanocrystals and a Nickel Catalyst

Homogeneous systems for light-driven reduction of protons to H2 typically suffer from short lifetimes because of decomposition of the light-absorbing molecule. We report a robust and highly active system for solar hydrogen generation in water that uses CdSe nanocrystals capped with dihydrolipoic acid (DHLA) as the light absorber and a soluble Ni2+-DHLA catalyst for proton reduction with ascorbic acid as an electron donor at pH 4.5, which gives >600,000 turnovers. Under appropriate conditions, the precious-metal-free system has undiminished activity for at least 360 hours under illumination at 520 nm and achieves quantum yields in water of over 36%. Read more here: http://www.sciencemag.org/content/early/2012/11/07/science.1227775