According to the U.S. Environmental Protection Agency (EPA), Americans spend about 90 percent of their time indoors, and the quality of that indoor air is important to everyone, and especially those with conditions like asthma or heart disease. Indoor air quality can be affected by a huge number of things, such as appliances that burn fuel, like gas stoves; the consumption of tobacco products; carpet, upholstery, or flooring that has been recently installed; high moisture levels; or things that can seep in from the outdoors, including radon, pollution, or smoke. Ventilation levels in a building also affect air quality, since some areas are well-ventilated while others may trap irritants.
There are some ways to improve indoor air quality, such as adding ventilation; or installing air filters or cleaners. But cumbersome and expensive systems may be required to truly improve indoor air quality, and those may not be available to most people.
Scientists are working to develop an easier way to make simple improvements to indoor air quality. Reporting in the journal Advanced Sustainable Systems, researchers have created a kind of artificial plant that can consume carbon dioxide and release oxygen. This device even generates a tiny bit of power in the process.
“Especially after going through COVID-19, we know the significance of indoor air quality,” said senior study author Seokheun “Sean” Choi, a Professor at Binghamton University. “Many sources can generate very toxic materials, like building materials and carpets. We breathe out and breathe in, and that builds up carbon dioxide levels. Also, there are risks from cooking and infiltration from the outdoors.”
After starting with a simple project just for fun, Choi and graduate student Maryam Rezaie realized their creation could have real applications. Next, they constructed an artificial plant with five 'leaves' made of biological solar cells, and tested its ability to capture carbon dioxide and generate oxygen.
It works using a kind of indoor photosynthesis mechanism that is powered by photosynthetic bacteria called cyanobacteria. Indoor light hits the bacteria, and they convert carbon dioxide and water to oxygen. The leaves consist of an anode that contains cyanobacteria, a cathode, plus an ion exchange membrane.
The artificial plant can reduce carbon dioxide levels in a room by as much as 90 percent. Natural plants only lower carbon dioxide levels by about ten percent, according to the researchers.
The device only creates about 140 microwatts of energy, and Choi is hoping to boost that output to one milliwatt or more. Power generation would be a secondary use, but it could eventually be used as a system to store energy or charge devices.
“I want to be able to use this electricity to charge a cell phone or other practical uses,” added Choi.
Other bacteria might be added to this system to make it viable over long periods of time, or reduce maintenance needs, such as the addition of water or nutrients. “With some fine-tuning, these artificial plants could be a part of every household,” Choi said. “The benefits of this idea are easy to see.”
Sources: Binghamton University, Advanced Sustainable Systems
