The Atomic-Level Structure of Mesoporous h-BN Revealed

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Mesoporous h-BN structure images
(Top, Left) SEM image of porous h-BN. (Top, Right) DFT calculated structural model of porous h-BN. (Bottom, Left) 2D 11B homonuclear correlation NMR spectrum recorded at B0 = 35.2 T (n0(1H) = 1.5 GHz). (Bottom, Right) Comparison of experimental 11B and 15N NMR spectra with DFT predicted NMR spectra.
Scientific Achievement

Solid-state NMR spectroscopy and plane-wave DFT reveal the structure of pores/defects of mesoporous hexagonal boron nitride (p-BN).

Significance and Impact

Detailed description of the molecular structure of the pores will facilitate the development of improved adsorption materials.

Research Details
  • 1H-15N heteronuclear correlation solid-state NMR experiments identify N-Hx (x = 1-3) species on the pore edges.
  • Ultra-high field 35.2 T 11B homonuclear correlation NMR experiments reveal that clusters of boron oxide connect to the BN framework via BN2O species.
  • 11B-15N heteronuclear correlation NMR experiments suggest that boron oxide terminations are abundant.
  • Plane-wave DFT calculations corroborate the presence of oxide and hydroxide terminated B and N-H terminated pores/defects.

R.W. Dorn, P.M. Heintz, I. Hung, K. Chen, J.S. Oh, T.H. Kim, L. Zhou, Z. Gan, W. Huang,* A.J. Rossini.* "Atomic-Level Structure of Mesoporous Hexagonal Boron Nitride Determined by High-Resolution Solid-State Multinuclear Magnetic Resonance Spectroscopy and Density Functional Theory Calculations," Chem. Mater., 2022,  34, 1649-1665.