A new study led by Wang Xianlong at the Hefei Institutes of Physical Science has resulted in the atmospheric pressure synthesis of cubic gauche nitrogen, a high-energy-density material with promising applications.
In a significant scientific breakthrough, researchers from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences have successfully synthesized cubic gauche nitrogen (cg-N) at atmospheric pressure. The research, led by Wang Xianlong, utilized potassium azide (KN3) and the plasma-enhanced chemical vapor deposition (PECVD) technique to achieve this milestone. The results of the study were recently published in the journal Science Advances.
Cubic gauche nitrogen is composed entirely of nitrogen atoms interconnected through N-N single bonds, mimicking the structure of diamond. This material has drawn considerable attention due to its high-energy-density and the fact that it decomposes into harmless nitrogen gas. Achieving a safe and efficient synthesis method for cg-N at atmospheric pressure has been an ongoing challenge in the field.
Since 2020, Wang’s team has employed first-principles calculations to simulate the stability of the cg-N surface under various conditions, including different pressures and temperatures. Their findings indicated that surface instability caused cg-N to decompose at low pressures. By saturating the surface suspension bonds and managing charge transfer, the researchers have now managed to stabilize cg-N up to 750 K at atmospheric pressure.
In their recent study, the team opted to use potassium azide, known for its lower toxicity and explosive risk, as the precursor. The strong electron transfer capability of potassium played a crucial role in the successful synthesis of cg-N using PECVD. This method did not require the previously essential carbon nanotube-limiting effect. Further validation came from thermogravimetric-differential scanning calorimetry (TG-DSC) measurements, confirming that the synthesized cg-N maintains thermal stability up to 760 K, though it undergoes rapid and intense decomposition at higher temperatures.
This advancement represents not only an efficient and convenient method for synthesizing cg-N at atmospheric pressure but also opens new avenues for developing high-energy-density materials. The potential applications of cg-N are vast, potentially transforming energy storage and other sectors reliant on high-energy materials.
The significance of this research is profound. High-energy-density materials like cg-N have the potential to revolutionize various industries, including aerospace, defense and energy storage, by providing more efficient and safer alternatives. As cg-N decomposes only into nitrogen gas, it offers an environmentally friendly solution, reducing potential hazardous byproducts.