Nanoporous membranes with atomic-scale holes hold significant potential for decontaminating polluted water, extracting valuable metal ions, and powering osmotic generators. However, their application has been limited by the slow process of creating sub-nanometer pores individually.
Eli Hoenig (PhD’23) addressed this challenge in a recent paper published in Nature Communications. Under the guidance of Chong Liu, Assistant Professor at the University of Chicago Pritzker School of Molecular Engineering, Hoenig and his team developed a method to generate multiple nanoscale pores simultaneously. This technique involves creating materials with intentional weak spots and using a remote electric field to form several pores at once.
“Our logic is that, if we can pre-design what the material looks like and design where the weak points are, then when we do the pore generation, the field will pick up those weaker points and start to drill holes there first,” said Liu.
By overlapping layers of polycrystalline molybdenum disulfide, the researchers can control where crystals meet. “Say I have two perfect crystals. When the two crystals come together, they will not be smoothly just glued together. There's an interface where they start to connect to each other,” Liu explained. This allows them to "pre-pattern" grain boundaries and control pore formation with precision.
The technique also enables fine-tuning of pore concentration and size—from 4 nanometers down to less than 1 nanometer—offering flexibility for various applications such as water treatment systems and fuel cells.
“People want to precisely create and confine pores, but usually the method is limited so that you can only create one pore at a time,” Liu stated. The new method allows high-density pore creation while maintaining control over each pore's size and precision.
Hoenig highlighted environmental applications as particularly promising. These include treating water and extracting resources like lithium needed for renewable energy storage solutions.
“Targeted water decontamination and resource recovery are, at least at this basic science level, two sides of the same coin, and both, to me, are really important,” he noted.
Liu mentioned that this research stemmed from collaboration with Prof. Shirley Meng's battery-focused lab and Asst. Prof. Shuolong Yang’s quantum group. Their joint efforts previously overcame challenges in growing quantum qubits on crystals.
“Our three teams are trying to develop precision synthesis techniques... Together, we are looking at how we can manipulate a material’s composition, structure, and defects to be able to create precise defects and pores,” Liu said.
Liu is working on commercializing this innovation through the University of Chicago Polsky Center for Entrepreneurship and Innovation.
Citation: “In situ generation of (sub) nanometer pores in MoS2 membranes for ion-selective transport” Hoenig et al., Nature Communications, Sept. 10, 2024. DOI: https://doi.org/10.1038/s41467-024-52109-8