A new, stable artificial photosynthesis device doubles the efficiency of harnessing sunlight to break apart both fresh and salt water, generating hydrogen that can then be used in fuel cells.
The device could also be reconfigured to turn carbon dioxide back into fuel.
Hydrogen is the cleanest-burning fuel, with water as its only emission. But hydrogen production is not always environmentally friendly. Conventional methods require natural gas or electrical power. The method advanced by the new device, called direct solar water splitting, only uses water and light from the sun.
“If we can directly store solar energy as a chemical fuel, like what nature does with photosynthesis, we could solve a fundamental challenge of renewable energy,” said Zetian Mi, a professor of electrical and computer engineering at the University of Michigan who led the research while at McGill University in Montreal.
Faqrul Alam Chowdhury, a doctoral student in electrical and computer engineering at McGill, said the problem with solar cells is that they cannot store electricity without batteries, which have a high overall cost and limited life.
The device is made from the same widely used materials as solar cells and other electronics, including silicon and gallium nitride (often found in LEDs). With an industry-ready design that operates with just sunlight and seawater, the device paves the way for large-scale production of clean hydrogen fuel.
Previous direct solar water splitters have achieved a little more than 1 percent stable solar-to-hydrogen efficiency in fresh or saltwater. Other approaches suffer from the use of costly, inefficient or unstable materials, such as titanium dioxide, that also might involve adding highly acidic solutions to reach higher efficiencies.
Mi and his team, however, achieved more than 3 percent solar-to-hydrogen efficiency. To reach this stable efficiency, the team built a nano-sized cityscape of gallium nitride towers that generated an electric field. The gallium nitride turns light, or photons, into mobile electrons and positively charged vacancies called holes. These free charges split water molecules into hydrogen and oxygen.
“When this specially engineered wafer is hit by photons, the electric field helps separate photogenerated electrons and holes to drive the production of hydrogen and oxygen molecules efficiently,” Chowdhury said.
At present, the silicon backing of the chip does not contribute to its function, but it could be doing more. The next step may be to use the silicon to help capture light and funnel charge carriers to the gallium nitride towers.
“Although the 3 percent efficiency might seem low, when put in the context of the 40 years of research on this process, it’s actually a big breakthrough,” Mi said. “Natural photosynthesis, depending how you calculate it, has an efficiency of about 0.6 percent.”
He adds that 5 percent efficiency is the threshold for commercialization, but his team is aiming for 20 or 30 percent efficiency.
Mi conducts similar research to strip carbon dioxide of its oxygen to turn the resulting carbon into hydrocarbons, such as methanol and syngas. This research path could potentially remove carbon dioxide from the atmosphere, like plants do.
“That’s the truly exciting part,” Mi said.
The Latest on: Artificial photosynthesis
via Google News
The Latest on: Artificial photosynthesis
Splitting water: Nanoscale imaging yields key insights
on July 18, 2018 at 8:05 am
In the quest to realize artificial photosynthesis to convert sunlight, water, and carbon dioxide into fuel -- just as plants do -- researchers need to not only identify materials to efficiently perfor... […]
Nanoscale imaging yields key insights into water splitting
on July 18, 2018 at 7:41 am
(Nanowerk News) In the quest to realize artificial photosynthesis to convert sunlight, water, and carbon dioxide into fuel – just as plants do – researchers need to not only identify materials to effi... […]
New ways of travelling light
on July 17, 2018 at 3:51 pm
The process has been replicated and we now have artificial photosynthesis. Carbon dioxide from sources like power plants can now be converted to other forms, with the release of oxygen. The energy tha... […]
Artificial Photosynthesis May Help Scientists Create Atmospheres in Space
on July 12, 2018 at 8:11 am
Elon Musk, Jeff Bezos, Lockheed Martin, and NanoRacks all love talking about how they want to colonize space. But there are obviously a few of logistical issues, including how to produce enough energy ... […]
Using Sunlight To Make Spaceship Fuel And Breathable Air
on July 10, 2018 at 11:03 am
That’s why some researchers are looking toward technology that they call artificial photosynthesis — a way of harnessing the sun’s light to generate fuel and breathable air for longer missions. This s... […]
Artificial Photo Synthesis Market Report Offers Ongoing Market Trends and Upcoming Growth Expectations
on June 13, 2018 at 8:43 pm
Pune, India -- (SBWIRE) -- 06/13/2018 -- Artificial Photosynthesis is relatively new technology which aims to mimic natural photosynthesis and produce clean energy. Photosynthesis is the process of co... […]
Chemists Develop Improved Method to Create Artificial Photosynthesis
on May 7, 2018 at 9:18 am
Newswise — A team of chemistry and chemical engineering researchers at the University of Arkansas has developed a method of creating materials for artificial photosynthesis that is more efficient and ... […]
Harvesting clean hydrogen fuel through artificial photosynthesis
on May 3, 2018 at 9:30 am
The colorized electron microscope image shows the gallium nitride towers of the artificial photosynthesis device at 52.5k magnification. These nanostructures rip water molecules apart into hydrogen an... […]
New catalyst catches the sun by improving artificial photosynthesis
on April 20, 2018 at 6:50 pm
A group of researches in the United States and China say their new dual-atom catalyst improves artificial photosynthesis - the ability to store the sun's energy the way plants do. Elly Park reports. A ... […]
via Bing News