New method may convert gaseous carbon dioxide into fuel

Scientists have found a potential new way to convert carbon dioxide emissions into energy-rich fuel using a very abundant natural resource: silicon.
Silicon, readily available in sand, is the seventh most-abundant element in the universe and the second most-abundant element in the Earth's crust.
The idea of converting carbon dioxide emissions to energy is not new. There has been a global race to discover a material that can efficiently convert sunlight, carbon dioxide and water or hydrogen to fuel for decades.
However, the chemical stability of carbon dioxide has made it difficult to find a practical solution.
"A chemistry solution to climate change requires a material that is a highly active and selective catalyst to enable the conversion of carbon dioxide to fuel," said Geoffrey Ozin from the University of Toronto (U of T).

"It also needs to be made of elements that are low cost, non-toxic and readily available," said Ozin.

Ozin and colleagues found that silicon nanocrystals meet all the criteria.
The hydride-terminated silicon nanocrystals have an average diameter of 3.5 nanometres and feature a surface area and optical absorption strength sufficient to efficiently harvest the near-infrared, visible and ultraviolet wavelengths of light from the Sun together with a powerful chemical-reducing agent on the surface that efficiently and selectively converts gaseous carbon dioxide to gaseous carbon monoxide.
The potential result: energy without harmful emissions, researchers said.
"Making use of the reducing power of nanostructured hydrides is a conceptually distinct and commercially interesting strategy for making fuels directly from sunlight," said Ozin.

The team is working to find ways and means to increase the activity, enhance the scale, and boost the rate of production.
The research was published in the journal Nature Communications.