Oxidation of acetylene black by nitric acid in hermetically sealed condition

Acetylene blacks were oxidized with nitric acid to obtain some insight into the mechanism of oxidative degradation in sealed condition. Changes in the morphologies and structures of acetylene blacks in the course of oxidation were investigated using transmission electron microscopy, X-ray diffraction, Raman, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and nitrogen adsorption and desorption isotherms. Time-dependent experiments were carried out to investigate the degree of oxidation. It was found that, with the increase of acid steaming duration ranging from 2, 4, 6 to 8 h, the yield of oxidized product decreases from 87.5%, 64.4%, 51.0% to 27.5%. Experimental results demonstrated that the prolonged treatment led to an increased hollow ratio and an enhanced degree of oxidation. The functionalized hollow sample was characterized and it was observed a well developed microporous and mesoporous structure.