Environment

Nanomotors could help reduce carbon dioxide pollution in oceans

Nanomotors could help reduce c...
Nanomotors quickly move through water, removing carbon dioxide as they go
Nanomotors quickly move through water, removing carbon dioxide as they go
View 1 Image
Nanomotors quickly move through water, removing carbon dioxide as they go
1/1
Nanomotors quickly move through water, removing carbon dioxide as they go

Climate change has a huge impact on the health of the world's oceans. In an attempt to find a solution for carbon dioxide pollution in the oceans, nanoengineers at the University of California, San Diego have developed micromotors that autonomously move through water, removing CO2 and converting it into usable material.

The nano machines are smaller than the width of a human hair and have an external polymer surface to hold the enzyme carbonic anhydrase, which acts to speed up the reaction between carbon dioxide and water to form bicarbonate. Calcium chloride is added to the water solutions to help convert bicarbonate to calcium carbonate. The autonomous and continuous movement of the micromotors through the water is also said to aid the mixing process, which leads to faster carbon dioxide conversion.

That movement is facilitated by the addition of a small amount of hydrogen peroxide to the solution, which reacts with the inner platinum surface of the micromotors and generates a stream of oxygen bubbles that propel them through the water at speeds exceeding 100 micrometers per second.

The researchers report that in the lab, the micromotors managed to remove 90 percent of the carbon dioxide from a solution of deionized water within five minutes. Similar efficiency was observed in a seawater solution, where the tiny machines removed 88 percent of the carbon dioxide. Once their job is done, the micromotors can be recovered from the water solution and reused for further carbon dioxide sequestration.

Though the water solutions in the proof-of-concept experiments contained only two to four percent hydrogen peroxide, the researchers acknowledge its use as fuel for the micromotors is less than ideal. This need for an additional additive, together with the expense of using platinum in the micromotors themselves, has prompted the nanoengineers to look into developing carbon-capturing micromotors that can use the water itself as fuel.

"If the micromotors can use the environment as fuel, they will be more scalable, environmentally-friendly and less expensive," said said Kevin Kaufman, co-author of the study and an undergraduate in the team led by nanoengineering professor and chair Joseph Wang. "In the future, we could potentially use these micromotors as part of a water treatment system, like a water decarbonation plant."

The research has been published in the journal Angewandte Chemie.

Source: University of California, San Diego

9 comments
MarkRickard
CO2 is not a pollutant, it's plant food.
Won't someone think of the phytoplankton?!
JoginderSinghKular
A novel method to reduce CO2( Carbon Dioxide) in ocean waters.If it is successful in commercial scale, it can revolutionize environmental cleaning
Douglas Bennett Rogers
Looks like it duplicates phytoplankton. Limitation is amount of uncarbonated calcium.
AbelGarcia
The problem here is living organisms use CO2 dissolved in water to build things like coral, sea grasses and etc.
Joseph Mertens
Nice tech But you could just build tanks next to the ocean or close off a small bay and just have a continuous algea bloom going then you would have bio feed stocks for fuel or animal feed or just stashing away (total waste but that's what PC folks do).
spicedreams
Where does the Calcium Chloride come from?

If we took calcium chloride and used, um, say, wave action to mix it with ocean water, would we need nano machines?
Rumata
Oceans contain ~140 000 000 000 000 tons of solved carbon dioxide.
Do you really think that human activity can have measureable effect on that?
In the Cretaceous age, when ocean life was the richest in Earth's history, the carbon dioxid level in the athmosphere were a magnitude higher.
Then how can you say that carbon dioxide is not good for ocean life?
Slowburn
Or you could just fertilize algae.
Alien
..and just how many of these nano entities would one expect to need in an ocean environment? At present, I doubt if they'd make much difference in anything bigger than a bath tub.
Nice technology though - and a step in the right direction.