Designer carbon materials enable CO2 release below 60 degrees Celsius

Mar 26, 2026

New carbon capture materials regenerate below 60 Celsius, low enough to use industrial waste heat, cutting the energy cost of the CO2 capture cycle.

(Nanowerk News) Researchers at Chiba University have synthesized a new class of nitrogen-doped carbon materials called viciazites that can release captured carbon dioxide at temperatures below 60 °C. By precisely controlling where nitrogen functional groups sit on the carbon surface, the materials could allow industrial carbon capture systems to run on waste heat instead of the energy-intensive regeneration processes used today.

Key Findings

Carbon capture is widely regarded as essential for curbing greenhouse gas emissions, yet most current methods remain costly. Aqueous amine scrubbing, the dominant industrial technique, absorbs CO2 into a liquid solvent that must then be heated above 100 °C to release the gas and reset the system. That thermal penalty drives up operating expenses and has slowed large-scale deployment. Solid carbon-based adsorbents offer a less energy-hungry alternative. These porous, inexpensive materials trap CO2 on their surfaces and release it at lower temperatures, particularly when their surfaces carry nitrogen-containing functional groups. However, conventional synthesis methods scatter these groups randomly and in mixed forms, making it impossible to determine which specific arrangement delivers the best performance. A team led by Associate Professor Yasuhiro Yamada from the Graduate School of Engineering and Associate Professor Tomonori Ohba from the Graduate School of Science at Chiba University addressed this gap. Their study, published in the journal Carbon (“Viciazites: Carbon materials with adjacent nitrogen functionalities for advanced CO2 capture”), and co-authored by Kota Kondo of Chiba University, introduces viciazites, carbon materials in which nitrogen groups occupy controlled, adjacent positions on the carbon surface. The team produced three distinct viciazites, each with a different adjacent nitrogen pairing. For adjacent primary amine groups (–NH2), they carbonized coronene at high temperature, treated the product with bromine, and exposed it to ammonia gas. This route placed 76% of all introduced nitrogen into the target adjacent amine configuration. A second material carrying adjacent pyrrolic nitrogen reached 82% selectivity, while a third with adjacent pyridinic nitrogen reached 60%. All three materials were coated onto activated carbon fibers to form practical adsorbent samples. Nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and computational modeling confirmed the nitrogen groups occupied adjacent positions rather than being distributed at random. Researchers from the Japan Advanced Institute of Science and Technology and Kindai University contributed to the characterization work. Testing revealed clear performance differences among the three configurations. Both adjacent amine and adjacent pyrrolic nitrogen materials captured more CO2 than untreated carbon fibers, while the pyridinic nitrogen variant showed little improvement. The most notable result involved desorption, the step where captured CO2 is released so the material can be reused. “Performance evaluation revealed that in carbon materials where NH2 groups are introduced adjacently, most of the adsorbed CO2 desorbs at temperatures below 60 °C. By combining this property with industrial waste heat, it may be possible to achieve efficient CO2 capture processes with substantially reduced operating costs,” highlights Yamada. The pyrrolic nitrogen material required higher temperatures for desorption but may offer better long-term durability because pyrrolic groups are more chemically stable than primary amines. That trade-off between regeneration temperature and material longevity could influence which viciazite type suits different industrial settings. By demonstrating that adjacent nitrogen configurations can be built deliberately and with high selectivity, the study provides a molecular-level design strategy for carbon capture adsorbents. “Our motivation is to contribute to the future society and to utilize our recently developed carbon materials with controlled structures. This work provides validated pathways to synthesize designer nitrogen-doped carbon materials, offering the molecular-level control essential for developing next-generation, cost-effective, and advanced CO2 capture technologies,” concludes Yamada. The researchers also note that viciazites may prove useful beyond CO2 capture. The precise and tunable surface chemistry of these materials could lend itself to metal ion adsorption and catalysis.