Abstract A new method for the production of boron nanoparticles is described. Boron trichloride is dissociated through injection into thermal plasma followed by a nucleation process producing boron nanoparticles. The ambient oxidation of the as-produced nanoparticles is also investigated. The nanoparticles were characterized with scanning transmission electron microscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy to investigate their purity and stability under ambient conditions