Effective Preparation of One-Dimensional Boron-Nitride- Nanotube-Supported Nanosheet Hierarchical Structures and Their Optical/Adsorption Properties

A novel boron nitride nanotube-supported nano-sheets one-dimensional hierarchical structures (BNNT-BNNS) were efficiently prepared via a ball milling assisting chemical vapor deposition method. X-ray powder diffraction (XRD), fourier transform infrared spectrometer (FTIR), Raman, field scanning electron microscopy (FSEM), energy dispersive spectroscopy (EDX), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were used to characterize the as-synthesized samples. The samples presented a length of more than 20m and wide diameter ranges from 20nm to 600nm. Abundant nano-sheets grew in random directions and intertwined closely on the surface of the one-dimensional structures. Every nano-sheet was transparent and demonstrated a thickness of less than 10nm with irregular size and shape. Ultraviolet-visible (UV-vis) and photoluminescence (PL) results indicated that the band gap was 5.71eV and the maximum fluorescence emission peak was located at 368nm. In addition, it was worth noting that the BNNT-BNNS hierarchical structures also presented excellent adsorption property for methylene blue (MB). When the adsorption time was 5min, MB could be removed by 75.2% from water solution. The adsorption rate could increase to 97.3% when the adsorption time was 115min. Finally, the possible chemical reactions and the corresponding catalytic cracking growth mechanism of the special hierarchical structures also were investigated carefully.