Indoor air quality is getting a photosynthetic boost by means of air-purifying artificial plants engineered by researchers from the State University of New York at Binghamton. In addition to feeding on indoor carbon dioxide, these devices also generate a small amount of electricity.

The cyanobacterial artificial plants described in Advanced Sustainable Systems stem from ongoing research about bacteria-powered biobatteries. The devices use indoor light to enable cyanobacteria to convert carbon dioxide and water into oxygen, thereby improving indoor air quality. Testing demonstrated a 90% reduction in carbon dioxide levels, far superior to the 10% reduction associated with natural plants.

Each artificial leaf contains five biological solar cells, each incorporating a cyanobacteria-infused anode, a cathode and an ion exchange membrane. The cells are interconnected electrically, via metallic paths, and fluidically, through a microfluidic channel. The power produced by the cyanobacteria totals about 140 microwatts, and the researchers plan to advance the technology to achieve a minimum output of more than 1 milliwatt and integrate lithium-ion batteries or supercapacitors for energy storage.

Hygroscopic hydrogels and iron oxide nanoparticles applied to the structure ensure continuous water and nutrient supply to individual leaves via capillary forces and promote light harvesting and carbon dioxide capture by the cyanobacteria. Reductions in indoor carbon dioxide levels from 5.000 ppm to 500 ppm and an increase in oxygen levels from 13.2 ppm to 22.9 ppm have been achieved.

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