Controlled fabrication of ultrathin-shell BN hollow spheres with excellent performance in hydrogen storage and wastewater treatment

Abstract

We developed a facile template-free solid state synthesis route, by which BN hollow spheres (BNHSs) with ultrathin shells (1–3 nm) were successfully prepared. Furthermore, the shell thickness of the BNHSs could be effectively adjusted by varying the reaction temperature. The as-prepared BNHSs with ultrathin shells possess high specific surface area, large pore volume and high density structural defects. These characteristics result in the excellent performance of BNHSs in hydrogen storage and adsorption of organic pollutants from wastewater. The hydrogen uptake capacity is up to 4.07 wt.% at 298 K and 10 MPa. The maximum adsorption capacities for basic yellow 1 and methylene blue are 191.7 and 116.5 mg g⁻¹, respectively. Besides, the BNHSs preferentially adsorb organic aromatic compounds from mixed solutions of aromatic dyes and heavy metal ions, so they can be used to separate and recover some valuable organic compounds from wastewater.