Artificial 'plants' could fuel future cars

Scientists have taken a big step towards creating artificial 'plants' that can use only sunlight to make gasoline and natural gas to run future cars without polluting the environment.
A research team has created an artificial leaf that produces methane, the primary component of natural gas, using a combination of semiconducting nanowires and bacteria.
The research builds on a similar hybrid system that yielded butanol, a component in gasoline, and a variety of biochemical building blocks.
It is a major advance towards synthetic photosynthesis, a type of solar power based on the ability of plants to transform sunlight, carbon dioxide and water into sugars.

Instead of sugars, however, synthetic photosynthesis seeks to produce liquid fuels that can be stored for months or years and distributed through existing energy infrastructure.
In a roundtable discussion on his recent breakthroughs and the future of synthetic photosynthesis, Peidong Yang, a professor at the University of California, Berkeley said his hybrid inorganic/biological systems give researchers new tools to study photosynthesis - and learn its secrets.

"We're good at generating electrons from light efficiently, but chemical synthesis always limited our systems in the past," said Yang, also a co-director of the Kavli Energy NanoSciences Institute.
"One purpose of this experiment was to show we could integrate bacterial catalysts with semiconductor technology. This lets us understand and optimise a truly synthetic photosynthesis system," said Yang.

"Burning fossil fuels is putting carbon dioxide into the atmosphere much faster than natural photosynthesis can take it out. A system that pulls every carbon that we burn out of the air and converts it into fuel is truly carbon neutral," said Thomas Moore, a professor of chemistry and biochemistry at Arizona State University.
Ultimately, researchers hope to create an entirely synthetic system that is more robust and efficient than its natural counterpart.
To do that, they need model systems to study nature's best designs, especially the catalysts that convert water and carbon dioxide into sugars at room temperatures.
"This is not about mimicking nature directly or literally," said Ted Sargent, the vice-dean of research for the Faculty of Applied Science and Engineering at University of Toronto.

"Instead, it is about learning nature's guidelines, its rules on how to make a compellingly efficient and selective catalyst, and then using these insights to create better-engineered solutions," said Sargent.
The study was published in the journal PNAS.