Scientists have found a way to harness nanoparticles and visible light to break down substances like bisphenol A (BPA) in wastewater and soil.

Various researchers have been trying to work out how sunlight could be used to eradicate pollutants with the potential to interfere with hormones in the body, known as endocrine disruptors. While a variety of photocatalysts have been designed toward this goal, efficient degradation of these pollutants has proved challenging. So far, approaches have focused on using ultraviolet light — but as this represents only 6 percent of sunlight, such methods are not very efficient.

Now, two researchers have developed a method that takes advantage of visible light, which comprises 52 percent of sunlight.

Nikhil R. Jana and Susanta Kumar Bhunia at the Centre for Advanced Materials, Indian Association for the Cultivation of Science, examined an existing graphene composite that uses visible light to degrade dyes. They altered the composite and loaded it with silver nanoparticles that serve as an antenna for visible light.

Testing showed that the new material successfully degraded three different kinds of endocrine disruptors: phenol, BPA and atrazine.

In the American Chemical Society journal ACS Applied Materials & Interfaces, Jana and Bhunia explain that their reduced graphene oxide (rGO)-based composite with silver nanoparticle (rGO-Ag) acted as an efficient visible-light photocatalyst for the degradation of colorless organic pollutants.

They said that they had developed a simple, large-scale synthesis method for rGO-Ag and this approach could also be extended for sunlight-induced degradation of other organic pollutants.