A group of researchers in China has developed a new type of membrane that could help turn acidic industrial wastewater into electricity.
Inspired by how certain proteins in bacteria work, this breakthrough could lead to cleaner, more efficient ways of generating energy.
The research team, from the Qingdao Institute of Bioenergy and Bioprocess Technology at the Chinese Academy of Sciences and Beihang University, designed a membrane that copies the function of a natural protein found in E. coli bacteria.
This protein, known as ClC-ec1, helps move chloride ions and protons (H⁺) across cell membranes.
To replicate this, the scientists combined two materials: covalent organic frameworks (COFs), which are porous and structured like a sponge, and aramid nanofibers (ANFs), which are strong, thread-like materials also found in bulletproof vests.
Together, these materials create a strong, stable membrane with tiny channels that mimic the way biological proteins transport particles.
One of the most exciting discoveries was that the membrane’s ability to move protons—an important part of generating electricity—improved a lot when just a tiny amount of chloride ions was added.
In fact, adding only 0.1% chloride ions boosted the proton movement rate by three times.
This effect did not happen when other types of ions, like nitrate or sulfate, were used. The chloride ions stretch the ANF chains and improve the network of hydrogen bonds, making it easier for protons to move through the membrane.
The researchers tested the membrane in acidic water that was similar to what comes from industrial waste.
They found that it could generate an energy output of 434.8 watts per square meter, one of the highest levels ever recorded for this kind of technology. Even more impressively, the membrane continued to work well for over 150 hours in a harsh, acidic environment.
This new membrane design could help solve two problems at once: cleaning up toxic acidic wastewater and producing clean energy from it.
Professor Zhu Ying from Beihang University, one of the study’s authors, said the research shows how copying nature can help tackle real-world challenges.
The team believes their design could lead to better technologies for both environmental cleanup and energy production in the future.
