2015-Spring. Reverse Cycle: Inspired by Leaves, a New Invention Turns Sunlight and Water into Fuel.

posted Apr 17, 2015, 10:54 AM by Alan Gould
By Chelsea Leu, California Magazine. For GSS Energy Use chapter 10. Excerpt: For the past ten years, Peidong Yang..., a professor in UC Berkeley’s Department of Chemistry, researches artificial photosynthesis, a process that mimics a leaf’s ability to convert sun, water, and carbon dioxide into fuel. But in his case, the fuel isn’t glucose—it’s gasoline. Last winter, Yang and his colleagues took a major step forward in achieving that goal. Their invention looks more like a small patch of moss than a leaf: It’s a papery green disk slightly bigger than a quarter. Yang and his colleagues describe it as a nanowire mesh made up of a network of nanometers-thick semiconductor wires that use the sun’s energy to break the chemical bonds in water. Dip one of these circles into a sunlit beaker of water, and hydrogen and oxygen come bubbling out. Yang hopes these circles will one day use carbon dioxide emitted by automobiles and water from the atmosphere to create fuels such as methane, methanol, and butanol. The result would be a fuel system that’s both carbon neutral and self-sustaining—a vast improvement on our current system, which involves digging carbon out of the earth in the form of oil, coal, or gas, and releasing it as exhaust into the atmosphere, where it contributes to climate change.  ...when asked if he’s proud of the work his lab has accomplished, Yang demurs. “We’re making progress,” he says. “But we’re not there yet.”... http://alumni.berkeley.edu/california-magazine/spring-2015-dropouts-and-drop-ins/reverse-cycle-inspired-leaves-new-invention