Chinese scientists have developed a universal green, high-efficiency membrane separation method to selectively extract a range of heavy metal resources critical to new energy technologies.
This offers a potential solution to long-standing challenges in traditional extraction techniques, such as high pollution, low efficiency, and high energy consumption, while also supporting critical metal recovery and recycling, Chinese Academy of Sciences (CAS) announced on Monday.
The accelerated advancement of China's dual carbon goals has fueled rapid growth in clean energy technologies such as wind power, photovoltaics, electric vehicles, and nuclear energy.
This growth has driven up demand for specific heavy metal elements, some of which face heavy import dependence and potential supply shortages, according to an article released by the CAS on its official WeChat account.
A joint research team made up of scientists from the State Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy at Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), CAS, and the Technical Institute of Physics and Chemistry, CAS, has developed a method for heavy metal extraction inspired by biological calcium ion channels.
They published the research results in the international academic journal Nature Nanotechnology, according to QIBEBT.
Traditional solvent extraction and adsorption methods rely on chemical binding to isolate heavy metal ions, often requiring large volumes of chemicals and causing environmental concerns.
While membrane-based techniques offer a cleaner alternative, they have historically struggled to distinguish between heavy metal ions due to their similar size and charge.
Drawing inspiration from biological systems, scientists observed that voltage-gated calcium channels act as selective pathways, allowing specific ions to pass while blocking others through what is known as the “anomalous mole fraction effect”.
Gao Jun, corresponding author of the study and researcher at QIBEBT, told Global Times that this mechanism enables precise ion selection at the microscopic level.
Building on this concept, the research team engineered microscopic channels approximately 1.4 nanometres wide, forcing target heavy metal ions to align in single file.
By coating the channels with chemicals designed to attract uranium, the system successfully replicated the biological effect, allowing uranium ions to pass while excluding competing elements such as vanadium.
In continuous testing using natural seawater over 22 days, the method efficiently extracted uranium while rejecting other background metals.
The technology can also be adapted for the extraction of metals such as copper and gold by modifying functional groups, enhancing its potential application.
The approach is expected to offer a more sustainable and efficient pathway for critical metal recovery, strengthen domestic mineral supply chains and contribute to the development of greener mining and recycling industries, according to reports.
