In a research revealed in Nature Chemical Engineering, researchers at EPFL developed a scalable technique for producing porous graphene membranes that effectively separate carbon dioxide.
The event may considerably scale back the fee and footprint of carbon seize applied sciences.
Capturing CO₂ from industrial emissions is important in addressing local weather change. Nevertheless, present strategies, reminiscent of chemical absorption, are each costly and energy-intensive. Graphene, a skinny, ultra-strong materials, has lengthy been thought of a possible different for gasoline separation. Nevertheless, producing giant, environment friendly graphene membranes has been difficult.
Led by Professor Kumar Agrawal of the Gaznat Chair in Superior Separations, researchers at EPFL have developed a scalable method to create porous graphene membranes that selectively filter CO₂ from gasoline mixtures. This technique reduces manufacturing prices whereas bettering membrane high quality and efficiency, which may facilitate real-world purposes in carbon seize and different areas.
Graphene membranes could be engineered with particular pores that permit CO₂ to cross by means of whereas blocking bigger molecules like nitrogen, making them very best for gasoline separation. These properties make them appropriate for capturing CO₂ emissions from energy crops and industrial processes. Nevertheless, producing these membranes at scale has been each troublesome and dear.
Most current strategies use costly copper foils to supply high-quality graphene, and the fragile dealing with usually leads to fractures that compromise membrane efficiency. The problem has been creating a cheap, constant technique for producing giant, high-quality graphene membranes.
The EPFL crew tackled these challenges by creating a technique to develop high-quality graphene on low-cost copper foils, considerably lowering materials prices. In addition they refined a chemical course of utilizing ozone (O₃) to etch microscopic pores into the graphene, enabling extremely selective CO₂ filtration.
The researchers enhanced the interplay between the gasoline and graphene, leading to uniform pore improvement throughout giant areas. It is a essential step towards making the expertise commercially scalable.
To deal with the difficulty of membrane fragility, the crew additionally developed a novel switch technique. As an alternative of floating the fragile graphene sheet onto a help, which frequently results in cracks, they employed a direct switch method inside the membrane module. This method eliminates dealing with challenges and reduces failure charges to almost zero.
Utilizing this novel technique, the researchers efficiently created 50 cm² graphene membranes with near-perfect integrity, surpassing earlier limitations. These membranes demonstrated sturdy gasoline permeance and CO₂ selectivity, successfully permitting CO₂ to cross by means of whereas blocking different gases.
Optimizing the oxidation course of elevated the density of CO₂-selective pores, additional bettering the membrane’s efficiency. Computational fashions confirmed that growing the gasoline circulation over the membrane was key to reaching these outcomes.
This improvement has the potential to considerably influence carbon seize expertise. Conventional CO₂ seize strategies depend on energy-intensive chemical processes, making them troublesome and dear for widespread use. In distinction, graphene membranes require no warmth enter and function by means of easy pressure-driven filtration, providing substantial vitality financial savings.
Past carbon seize, this expertise might be utilized to separate different gases, reminiscent of hydrogen and oxygen. With its scalable manufacturing method and low-cost parts, this breakthrough brings graphene membranes nearer to industrial viability.
GAZNAT, the Swiss Federal Workplace of Vitality, Bridge (Proof of Idea), and the Canton of Valais funded the research.
Journal Reference:
Hao, J. et al. (2025) Scalable synthesis of CO2-selective porous single-layer graphene membranes. Nature Chemical Engineering. doi.org/10.1038/s44286-025-00203-z
