An upcycling technology that selects and recovers valuable metals from discarded waste plastics to be reborn as an adsorbent has been developed.
The National Research Foundation of Korea announced on the 9th that a joint research team, including Professors Lee Jeong-hyun and Won Wang-yeon from Korea University, has developed an adsorbent capable of effectively recovering precious metals such as gold, palladium, and platinum from wastewater by processing polyvinyl chloride (PVC) waste plastics in their original form. This research was published online in the international journal Advanced Science on May 9.
Precious metals, which are high-value and rare resources, are widely used in various industries, including electronics, catalysts, and batteries. Therefore, the development of technology to recover precious metals from electronic waste or used catalysts is becoming increasingly important.
In particular, adsorbent-based precious metal recovery technology is gaining attention due to its simple process and low expense. However, existing adsorbents have the limitation of poor adsorption performance and complicated manufacturing processes, and toxic substances are used during this process.
The research team proposed a new strategy to manufacture precious metal adsorbents using PVC waste plastics. They removed impurities from the PVC waste plastics through a simple solvent treatment process and created a porous structure, then attached a "hydrazine" functional group that selectively adsorbs precious metals.
As a result of applying the developed adsorbent to the leachate of actual discarded computers and used catalysts, it selectively adsorbed precious metals even in an environment with various mixed metals. The initial performance was maintained almost entirely even when the same adsorbent was reused multiple times.
Additionally, the adsorbent with adsorbed precious metals was heat-treated to easily recover high-purity precious metals. A quantitative analysis of the economic and environmental aspects of this gold recovery process showed higher economic viability and environmental friendliness compared to existing gold mining and refining processes.
Professor Lee Jeong-hyun noted, "It is significant to propose a strategy for rebirthing discarded waste plastics as high-value materials in a simple and eco-friendly manner," adding, "The goal is to develop high-value materials using various types of waste plastics and natural polymers in the future."
References
Advanced Science (2025), DOI: https://doi.org/10.1002/advs.202503157