Robust 3D Boron Nitride Nanoscaffolds for Remarkable Hydrogen Storage Capacity from Ammonia Borane

Abstract

Mesoporous monolithic (3D) boron nitride (BN) structures are synthesized using a template-assisted polymer-derived ceramic route. Polyborazylene is selected to impregnate monolithic activated carbon, which is used as template. After pyrolysis and template removal, this method supplies BN compounds with controlled crystallinity and tunable textural properties controlled by the temperature at which they have been annealed (from 1000 to 1450 °C). Monoliths with an interconnected mesoporous network, high specific surface areas from 584 to 728 m2 g−1, significant pore volumes from 0.75 to 0.93 cm3 g−1, and a relatively high compressive strength are generated. These highly porous compounds are used as nanoscaffolds to confine ammonia borane (AB). The composites provide an effective gravimetric hydrogen capacity of up to 8.1 wt %, based on AB measured at 100 °C; this value demonstrates the high potential of this system as a safe potential hydrogen storage material.