Researchers have now edged closer toward this dream technology, developing what they describe as a game-changing solar cell that produces hydrocarbon fuels in the lab, with potential applications ranging from large-scale uses on Earth to providing power on Mars.

The prospect of using sunlight to power our energy-intensive lifestyles has enough merit on its own, but what if we could suck carbon dioxide out of the atmosphere while we're at it? This two-pronged environmental panacea has inspired scientists eyeing a greener future, with artificial leaves, hybrid energy systems and moth-inspired photoelectrochemical cells just a few examples of how we are progressing toward this goal.

Scientists at Chicago's University of Illinois have been working with new kinds of chemicals with new kinds of properties to take these efforts to the next level. The key, they say, is to discover a new type of catalyst that can turn atmospheric CO2 into burnable fuels in an efficient and inexpensive way.