Cubic left nitrogen with high energy density successfully synthesized at atmospheric pressure

A research group led by Professor Wang potassium azide (KN₃) using the plasma-enhanced chemical vapor deposition (PECVD) technique.

The research is published in Scientific advances.

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

Since 2020, the research team has used first-principles calculations as a theoretical guide to simulate the stability of the cg-N surface in various saturated states, pressures and temperatures. The results revealed that surface instability led to the decomposition of cg-N at low pressure. They proposed that saturation of surface suspension bonds and charge transfer could stabilize cg-N up to 750 K at atmospheric pressure.

In this research, choosing KN₃ With lower toxicity and explosiveness as a precursor due to the strong electron transfer capacity of potassium, the team successfully synthesized cg-N using PECVD technology without relying on the limiting effect 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.

The study provides an efficient and practical way to synthesize cg-N at atmospheric pressure, and also provides new ideas for the development of future high energy density materials, according to the team.