A Cornell University-led research team has developed a method for extracting gold from electronics waste, then using the recovered precious metal as a catalyst for converting carbon dioxide (CO2), a greenhouse gas, to organic materials.
The method could provide a sustainable use for some of the approximately 50 million tons of e-waste discarded each year, only 20% of which is recycled, according to Amin Zadehnazari, a postdoctoral researcher in the lab of Alireza Abbaspourrad, professor of food chemistry and ingredient technology.
Zadehnazari synthesized a pair of vinyl-linked covalent organic frameworks (VCOFs) to remove gold ions and nanoparticles from circuit boards in discarded electronic devices. One of his VCOFs was shown to selectively capture 99.9% of the gold and very little of other metals, including nickel and copper, from the devices.
“We can then use the gold-loaded COFs to convert CO2 into useful chemicals,” Zadehnazari said. “By transforming CO2 into value-added materials, we not only reduce waste disposal demands, we also provide both environmental and practical benefits. It’s kind of a win-win for the environment.”
Abbaspourrad is corresponding author and Zadehnazari lead author of “Recycling E-waste Into Gold-loaded Covalent Organic Framework Catalysts for Terminal Alkyne Carboxylation,” which published in Nature Communications.
Electronics waste is a literal gold mine: It’s estimated that a ton of e-waste contains at least 10 times more gold than a ton of the ore from which gold is extracted. And with an anticipated 80 million metric tons of e-waste by 2030, it’s increasingly important to find ways to recover that precious metal.
Traditional methods for recovering gold from e-waste involve harsh chemicals, including cyanide, which pose environmental risks. Zadehnazari’s method is achieved without hazardous chemicals, using chemical adsorption — the adhesion of particles to a surface.
The research made use of the Cornell Center for Materials Research and the Cornell NMR facilities, both of which are funded by the National Science Foundation.
