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Hydrogen Fuel from Sunlight

By Guest PostSeptember 13, 2013Sciencealexandra krawicz, artificial photosynthesis, berkeley lab, caltech, carbohydrate sugars, carbon dioxide, carbon dioxide reduction, earth abundant elements, eitan anzenberg, free electrons, gallium phosphide, gary moore, generate electricity, green sustainable energy, hydrogen fuel, hydrogen ions, hydrogen producing catalysts, ian sharp, jinhui yang, junko yano, non photoactive substrates, photoelectrochemical operations, protons, sunlight

Berkeley Lab Researchers at Joint Center for Artificial Photosynthesis Make Unique Semiconductor/Catalyst Construct

In the search for clean, green sustainable energy sources to meet human needs for generations to come, perhaps no technology matches the ultimate potential of artificial photosynthesis. Bionic leaves that could produce energy-dense fuels from nothing more than sunlight, water and atmosphere-warming carbon dioxide, with no byproducts other than oxygen, represent an ideal alternative to fossil fuels but also pose numerous scientific challenges. A major step toward meeting at least one of these challenges has been achieved by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) working at the Joint Center for Artificial Photosynthesis (JCAP).

“We’ve developed a method by which molecular hydrogen-producing catalysts can be interfaced with a semiconductor that absorbs visible light,” says Gary Moore, a chemist with Berkeley Lab’s Physical Biosciences Division and principal investigator for JCAP. “Our experimental results indicate that the catalyst and the light-absorber are interfaced structurally as well as functionally.” (more…)

A Dual Look at Photosystem II Using the World’s Most Powerful X-Ray Laser

By Guest PostFebruary 27, 2013Sciencealgae, berkeley lab, carbon dioxide, catalytic activities, cryogenic temperatures, cyanobacteria, data, earth, energy, free electron laser, green plants, jan kern, junko yano, laser pulses, lcls, light source, linac coherent, living cells, manganese calcium, metal ion, metalloenzyme crystal, metalloenzymes, mn4ca, molecular oxygen, most powerful, natural photosynthesis, nicholas sauter, nitrogen fixation, oxidation states, photo reduction, photon step cycle, photon steps, photosystem, protein complex, proteins, radiation damage, roberto alonso mori, s1 to s4, sensitive to radiation, simulate solar photons, slac, software tools, sunlight, uwe bergmann, vital to life, vittal yachandra, water, water molecules, world, xes, xfel, xray beams, xray diffraction, xray emission spectroscopy, xray laser, xrd

Berkeley Lab and SLAC Researchers Demonstrate Room Temperature Simultaneous Diffraction/Spectroscopy of Metalloenzymes

From providing living cells with energy, to nitrogen fixation, to the splitting of water molecules, the catalytic activities of metalloenzymes – proteins that contain a metal ion – are vital to life on Earth. A better understanding of the chemistry behind these catalytic activities could pave the way for exciting new technologies, most prominently artificial photosynthesis systems that would provide clean, green and renewable energy. Now, researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the SLAC National Accelerator Laboratory have taken a major step towards achieving this goal.

Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the world’s most powerful X-ray laser, the researchers were able to simultaneously image at room temperature the atomic and electronic structures of photosystem II, a metalloenzyme critical to photosynthesis. (more…)

A New Way of Looking at Photosystem II

By Guest PostJune 14, 2012Sciencealgae, angstroms, bacteria, berkeley lab, carbon dioxide, catalytic cycle, critical formation, cryogenic freezing, electrochemical energy, electrons, femtosecond timescale, femtosecond x ray pulses, green, green plants, hydrogen atom, hydrogen ions, jan kern, junko yano, knowledge, lcls, microcrystals, nicholas sauter, oxidation states, oxygen molecules, paul adams, photooxidation, photosynthesis, photosystem ii, protein crystallography, proteins, protons, renewable energy, resolution, slac, solar energy, synchrotron radiation, terabytes of data, uwe bergmann, vittal yachandra, water, xray diffraction, xrays

Berkeley Lab and SLAC Researchers Study Key Protein Complex Crucial to Photosynthesis

Future prospects for clean, green, renewable energy may hinge upon our ability to mimic and improve upon photosynthesis – the process by which green plants, algae and some bacteria convert solar energy into electrochemical energy. An artificial version of photosynthesis, for example, could use sunlight to produce liquid fuels from nothing more than carbon dioxide and water. First, however, scientists need a better understanding of how a large complex of proteins, called photosystem II, is able to split water molecules into oxygen, electrons and hydrogen ions (protons). A new road to reaching this understanding has now been opened by an international team of researchers, led by scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and SLAC National Accelerator Laboratory.

Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the research team produced the first ever images at room temperature of microcrystals of the photosystem II complex. Previous imaging studies, using X-rays generated via synchrotron radiation sources, required cryogenic freezing, which alters the samples. Also, to catalyze its reactions, photosystem II relies upon an enzyme that contains a manganese-calcium cluster that is highly sensitive to radiation. With the high-intensity femtosecond X-ray pulses of the LCLS, the research team was able to record intact images of these clusters before the radiation destroyed them. (more…)

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Hydrogen Fuel from Sunlight

A Dual Look at Photosystem II Using the World’s Most Powerful X-Ray Laser

A New Way of Looking at Photosystem II