Geoffrey Ozin and his colleagues believe they have found a way to convert CO? emissions into energy-rich fuel.
TORONTO, US: Every year, humans advance climate change and global warming – and quite likely our own eventual extinction – by injecting about 30 billion tonnes of carbon dioxide (CO2) into the atmosphere.
A team of University of Toronto (U of T) scientists believes they’ve found a way to convert all these emissions into energy-rich fuel in a carbon-neutral cycle that uses 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 CO2 emissions to energy isn’t new: there’s 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 CO2 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 CO2 to fuel. It also needs to be made of elements that are low cost, non-toxic and readily available,” said Geoffrey Ozin, the Canada research chair in materials chemistry and lead of U of T’s solar fuels research cluster.
In the journal Nature Communications, Ozin and colleagues report silicon nanocrystals that meet all the criteria. The hydride-terminated silicon nanocrystals – nanostructured hydrides for short – have an average diameter of 3.5 nanometers 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.
“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 U of T Solar Fuels Research Cluster is working to find ways and means to increase the activity, enhance the scale, and boost the rate of production. Their goal is a laboratory demonstration unit and, if successful, a pilot solar refinery.
© University of Toronto News