Novel BN porous-hollow nanorods: synthesis, tunable dimensions, property and formation mechanism

Abstract

In this paper, we used a high pressure benzene-thermal method to successfully prepare novel BN porous-hollow nanorods. Herein, thiophene is introduced as a catalyst to eliminate the benzene carbonization at high temperature. The alveolate porous wall of the nanorods is stacked up by small nanoflakes aligned vertically in the axial direction. In the high pressure solvothermal system, the diameter and wall thickness of the nanorods can be simply adjusted by the content of thiophene, temperature and pressure. A possible “gas–liquid–solid” mechanism is proposed to explain the formation of 1D BN nanorods. Another novel formation mechanism of the hollow nanorods is elaborated by observing the evolution process of the porous-hollow nanostructures. The method may provide a new idea to be used in preparing other porous-hollow nanostructures. In addition, the hierarchical porous-hollow nanorods exhibit an excellent hydrogen uptake property of 2.6 wt% at 298 K and 90 bar. In particular, the adsorption capacity per unit specific surface area was calculated to be 2.2 × 10⁻² wt% m⁻² g. This is a rather high value of hydrogen adsorption capacity for BN nanomaterials.