POWERING THE PLANET: A Chemical Bonding Center in the Direct Conversion of Sunlight into Chemical Fuel (California Institute of Technology)
Researchers at the Powering the Planet Center for Chemical Innovation have created an artificial leaf. Just as a natural leaf converts sunlight into water, oxygen and sugar, this stand-alone device captures solar energy and splits water into hydrogen and oxygen gas.
To compete with cheap fossil fuels, novel materials are needed to generate fuels from solar energy. The materials must be inexpensive and abundant and their production simple and low-cost. Through a sustainable distribution infrastructure, the artificial leaf could become a viable energy source for both developed and developing countries.
The artificial leaf converts sunlight into chemical fuel using a silicon photovoltaic cell and relatively inexpensive catalysts-materials that jump-start chemical reactions. The hydrogen catalyst is made from an alloy of nickel, molybdenum and zinc, while the oxygen catalyst is made from the element cobalt. These catalysts enable proton-coupled electron transfer-a process that occurs in nature when plants change water into oxygen.
Like Mother Nature's leaves, the artificial leaf self-assembles, operates in natural water at room temperature and self-heals. When immersed in water in the presence of sunlight, the catalyst-coated silicon wafer produces hydrogen and oxygen bubbles.
Technique helps researchers visualize light emission from a single moleculeResearch Areas: Chemistry & Materials Locations: California
Plant pollen in deep sea drill cores points to persistence of tropical forests in the AntarcticResearch Areas: Earth & Environment, Polar Locations: California, International