A novel 3D network nanostructure constructed by single-crystal nanosheets of B4C

Three-dimensional (3D) network nanostructure boron carbide was successfully synthesized via the carbothermic method. The carbon source and template was carbonized bacterial cellulose (CBC) with a 3D network nanostructure, and the boron source was B2O3 and amorphous B powder. X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS) were used to study the morphology and structure of the samples. XRD and Raman spectra confirm that they belong to the B4C crystalline phase. The FESEM images show that the synthetic B4C retains the 3D network nanostructure of the template CBC well and consists of B4C nanosheets with an average thickness of less than 100 nm. The analytical results of high-resolution TEM (HRTEM) and Selected Area Electron Diffraction (SAED) indicate that the B4C takes the shape of hexagonal single crystals with a rhombohedral structure. These B4C single crystal nanosheets alternate, forming the 3D network nanostructure. The mechanism of formation can be accounted for by in situ reduction reactions along the carbon nanofibers of CBC.