Photo-thermal Decomposition of Hexanitrostillbene (HNS) Surface by 532 nm Laser Irradiation: Spectral and Quantitative Analysis Using in situ X-ray Photoelectron Spectroscopy (XPS) Quadrupole Mass Spectrometry (MS) Technique
Y. Sun and Y-W. Xu
A novel approach to study the photo-thermal decomposition of hexanitrostillbene (HNS) (2, 2’, 4, 4’, 6, 6’) at 532 nm induced by a 10 nanosecond laser was described. In this method, an in situ X-ray photoelectron spectroscopy (XPS) – laser-quadrupole mass spectrum on-line equipment was designed elaborately. The new peak at the binding energy of 399.7 eV of N 1s XPS spectra and 288.6 eV of C 1s spectra showed that the nitro-nitrite isomerization with subsequent release of NO occurred in the laser-induced decomposition of HNS. The new peak at 30 m/z of mass spectra is also associated with the mechanism of nitro-nitrite isomerization of the HNS molecule with subsequent release of NO. Quantum chemistry calculation results are in good agreement with the experimental results. We attributed this laser-induced decomposition as the photo-thermal decomposition for the high temperature risen due to the laser irradiation.
Keywords: Laser, hexanitrostillbene (HNS), photo-thermal decomposition, in situ XPS, nitro-nitrite isomerization