Succeeded in synthesizing high-energy density cubic gauche nitrogen at atmospheric pressure

A research group led by Professor Wang Xianlong of the Hefei Institute of Physical Sciences, Chinese Academy of Sciences has successfully synthesized the high-energy density material cubic gauche nitrogen (CG-N) at atmospheric pressure by processing potassium azide (KN3). did. Uses plasma-enhanced chemical vapor deposition technology (PECVD).

The study is published in Science Advances.

Cg-N is a pure nitrogen material with nitrogen atoms connected by NN single bonds, similar to the structure of diamond. It is attracting attention because it has a high energy density and only produces nitrogen gas when decomposed. The development of efficient and safe synthetic methods under atmospheric pressure is an important challenge.

Since 2020, the research team has employed ab initio calculations as a theoretical guide to simulate the stability of the CG-N surface under various saturation conditions, pressures, and temperatures. The results revealed that surface instability causes the decomposition of cg-N under low pressure. They proposed that cg-N could be stabilized up to 750 K at atmospheric pressure by saturating surface suspension bonds and transferring charge.

In this study, we selected KN3 as a precursor, which has low toxicity and explosiveness due to the strong electron transfer ability of potassium, and succeeded in synthesizing CG-N using PECVD technology without relying on the limiting effect of carbon nanotubes. .

Thermogravimetric differential scanning calorimetry (TG-DSC) measurements confirmed that the synthesized cg-N exhibits thermal stability up to 760 K, followed by rapid and intense thermal decomposition.

According to the research team, this work provides an efficient and convenient way to synthesize CG-N at atmospheric pressure and also provides new ideas for the development of future high-energy density materials.