Coating Aluminum Borate (Al18B4O33) Nanowire Webs with BN

A facile method was proposed to directly synthesize the completely coated aluminum borate (Al18B4O33) nanowire webs with BN by an epitaxial growth process. The BN-Al18B4O33 nanocable webs could be obtained by the reaction of Al18B4O33 nanowire webs, B2O3, and ammonia at 1200 degrees C. The high-temperature stable Al18B4O33 nanowire webs acted as a template for the epitaxial coating of BN. The coating was characterized by the means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and infrared spectrum (IR). High-resolution transmission electron microscopy (HRTEM) clearly shows the BN coating layers closely attached to the inner nanowires. The typical thickness of the BN shells is similar to 5 nm. The growth mechanism of the present BN-coated aluminum borate (Al18B4O33) nanostructures was also proposed.