Cubic gauche polymeric nitrogen under ambient conditions

Abstract

The long-sought cubic gauche phase of polymeric nitrogen (cg-PN) with nitrogen-nitrogen single bonds has been synthesized together with a related phase by a radio-frequency plasma reaction under near-ambient conditions. Here, we report the synthesis of polymeric nitrogen using a mixture of nitrogen and argon flowing over bulk β-sodium azide or β-sodium azide dispersed on 100 nm long multiwall carbon nanotubes. The cg-PN phase is identified by Raman and attenuated total reflection-Fourier transform infrared spectroscopy, and powder X-ray diffraction. The synthesis of the cubic gauche allotrope of high energy density polymeric nitrogen under near-ambient conditions should therefore enable its optimized production and applications as a “green” energetic material and a potential catalyst for different chemical reactions.

N8− Polynitrogen Stabilized on Nitrogen-Doped Carbon Nanotubes as an Efficient Electrocatalyst for Oxygen Reduction Reaction

“…However, the presence of the peak around 2700 cm −1 in 2D position over NCNT sample suggests the long-range ordering of graphitic structure. For NaN 3 /CNT sample, the sharp peak around 1360 cm −1 associated with sodium azide overlaps with the carbon nanotube D (defect) mode [32], which is also observed on NaN 3 /NCNT. Interestingly, the spectrum of PN-CNT sheet clearly depicts a line at 1077 cm −1 , other than those from CNT.…”

“…The morphology of PN species was characterized by TEM as illustrated in Figure 2a. It clearly showed that PN species deposited on the outer-, intra-, and inter-layers of the nanotubes [32,36]. To investigate the thermal stability and quantify the amount of the synthesized PN species, temperature-programmed decomposition (TPD) was performed over different samples as displayed in Figure 2b.…”

“…A large amount of energy (2.3 eV per atom) is expected to be released upon transforming singly bonded nitrogen to diatomic triply bonded molecular nitrogen [32]. Therefore, polynitrogen compounds have attracted much attention due to their high-energy density while its experimental synthesis is challengeable [33][34][35].…”

Confinement of the Pentanitrogen Cation Inside Carbon Nanotubes

“…In recent years, different PN clusters and molecular crystals were theoretically predicted and some were experimentally obtained [14][15][16][17][18][19][20]. In 2017, two main achievements renovated once again the interest in the field, namely the isolation and characterization of cyclo-N − 5 pentazolate [21] and the synthesis of the cubic gauche form of nitrogen under near-ambient conditions [22]. Despite the recent successes, other ways to stabilize (and hopefully store) singleand double-bonded PN clusters were proposed too, in particular molecular confinement.…”

“…By spatially confining PN clusters inside the cavity of such materials, thanks to less geometrical freedom as well as non-bonded interactions with the hosting system, the guest fragments may be favorably stabilized and stored. First investigations in this direction have proposed the encapsulation of nitrogen chains inside carbon nanotubes and have theoretically predicted, as well as later experimentally observed, the feasibility of this approach [22][23][24][25][26][27]. Besides carbon nanotubes, other types of carbon nanostructures as well as other nanomaterials have been proposed as valid alternatives [28][29][30][31][32].…”