Gold is famous for being used to support monetary policies, but the prized metal can also play a big role in CO2 reduction. Namely, gold can be used to convert carbon dioxide (CO₂) into useful organic chemicals by acting as a catalyst through the carboxylation process. Unlike other metals, though, gold selectively interacts with CO2, while ignoring other gases, and doesn’t corrode easily.
However, gold is also expensive. Moreover, there is quite a lot of gold nanoparticles present in e-waste, of which 50 million tons are discarded globally each year. Unfortunately, only 20% of that e-waste is recycled, although e-waste is full of precious metals. For example, e-waste contains 10 times more gold per ton than raw ore, which is currently untapped.
That might soon change, though, as researchers from Cornell University developed a groundbreaking method to extract gold from e-waste. “There’s an immense opportunity in e-waste. By recovering gold from electronics, we’re not just reducing waste but also putting that resource to work in cutting CO2 emissions,” explained Amin Zadehnazari, postdoctoral researcher and lead author of the study.
The research, published in Nature Communications, details how Zadehnazari synthesized vinyl-linked covalent organic frameworks (VCOFs) capable of selectively capturing 99.9% of gold from circuit boards while leaving behind less valuable metals like nickel and copper. Once extracted, gold ions and nanoparticles can be used to catalyze CO2 conversion into usable chemicals. Gold nanoparticles are of particular interest in the study, because of their high surface area, which accelerates reactions even at low concentrations.
“Instead of relying on hazardous chemicals like cyanide, our approach uses chemical adsorption,” Zadehnazari said. “The gold-loaded frameworks can handle repeated cycles without losing efficiency, making this a sustainable and scalable process.”
This gold-extraction process could prove to be a crucial tool in the fight against climate change, while also boosting the circular economy, where waste becomes a resource. Moreover, it addresses the growing mountain of discarded electronics. With e-waste predicted to surge to 80 million metric tons by 2030, recovering these valuable metals is becoming increasingly essential.
Article source by Nature Communications
Image source by Stan Hutter on Unsplash
