by • July 28, 2016 • No Comments
Recreating a plant’s capacity to use sunlight to turn carbon dioxide into fuel, a thing known as artificial photosynthesis, is one of the holy grails of green energy research. Researchers have now edged nearer in the direction of this dream innovation, developing what they describe as a game-changing solar cell that produces hydrocarbon fuels in the lab, with following applications ranging of large-scale uses on planet Earth to providing power on Mars.
The prospect of via sunlight to power our energy-intensive lifestyles has adequate merit on its own, but what if we may suck carbon dioxide out of the atmosphere while we’re at it? This two-pronged environmental panacea has inspired scientists eyeing a greener following, with artificial leaves, hybrid energy systems and moth-inspired photoelectrochemical cells only a few examples of how we are progressing in the direction of 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 following 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.
In pursuit of this, the team was working with a set of nanostructured compounds called transition metal dichalcogenides, or TMDCs. It happened upon one TMDC called nanoflake tungsten diselenide that, when paired with water and a particular ionic liquid as the electrolyte, worked 1,000 times faster than the expensive metals usually utilized in these CO2 reduction technologies. The fact that it is of 20 times cheaper didn’t injure either.
“The active sites of the catalyst get poisoned and oxidized,” says Amin Salehi-Khojin, senior author on the study. “The combination of water and the ionic liquid makes a co-catalyst that preserves the catalyst’s active sites under the complex reduction reaction conditions.”
The solar cell itself is created up of two silicon triple-junction photovoltaic cells measuring 18 cm sq (2.8 in sq) to harvest the light, with the co-catalyst system on the cathode side and cobalt oxide in potassium phosphate electrolyte on the anode side.
When 100 W of light per meter squared hits the cell, around the same as the average intensity hitting the planet Earth’s surface, it kicks off a chemical reaction where hydrogen and carbon monoxide gas are produced of the cathode. Free oxygen and hydrogen ions are produced at the anode. This reaction produces synthesis gas, or syngas, that can be burned as is or turned into diesel and other hydrocarbon fuels.
According to the team, the solar cell may be modified
to large-scale use such as solar farms, along with smaller in size applications. One day, it can actually provide power on Mars if water can be discovered there, as the planet’s atmosphere is largely carbon dioxide.
“The new solar cell is not photovoltaic — it is photosynthetic,” says Salehi-Khojin. “Instead of making energy in an unsustainable one-way route of fossil fuels to greenhouse gas, we can now reverse the system and recycle atmospheric carbon into fuel via sunlight.”
The research was published in the journal Science.
Source: University of Illinois
by admin • March 5, 2017
by admin • November 28, 2016
by admin • November 28, 2016