Characterization and synthesis mechanism of Co3O4 nanoparticles synthesized by the emulsion detonation method

Tricobalt tetraoxide (Co3O4) nanoparticles have excellent applications in the fields of electricity, photocatalysis, and ceramics, whereas conventional synthesis methods require sophisticated equipment, strictly controlled conditions, and long duration. Herein, a new method for the synthesis of Co3O4 nanoparticles was proposed. In this emulsion detonation method, the precursor cobalt nitrate hexahydrate (Co(NO3)2·6H2O) was added during the production of the explosives and was therefore more uniformly dispersed than in other detonation methods. The preparation and detonation durations of the explosives were on the scale of minutes and microseconds, respectively, which are much shorter than those in other nanomaterial synthesis methods. The collected products were briefly purified and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometer, field emission scanning electron microscopy, and field emission transmission electron microscopy. Cyclic voltammetry and galvanostatic charge–discharge measurements were performed. The results show that the synthesized products were of high purity and consisted mainly of sphere-like particles with a dimensional distribution of approximately 50 nm. The electrochemical properties of these Co3O4 nanoparticles were similar to those synthesized by conventional methods. Combined with the detonation theory and the initial composition of the products, the analysis showed that the synthesis mechanism is mainly divided into two stages: formation and polymerization. Therefore, this approach could provide a new and effective synthesis method for the low-cost production of Co3O4 nanoparticles.