Atomic-Level Structure of Mesoporous Hexagonal Boron Nitride Determined by High-Resolution Solid-State Multinuclear Magnetic Resonance Spectroscopy and Density Functional Theory Calculations

Date
2022-02-08
Authors
Dorn, Rick
Heintz, Patrick M.
Hung, Ivan
Chen, Kuizhi
Oh, Jin-Su
Kim, Tae-Hoon
Zhou, Lin
Gan, Zhehong
Huang, Wenyu
Rossini, Aaron
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
American Chemical Society
Altmetrics
Authors
Research Projects
Organizational Units
Chemistry
Organizational Unit
Ames Laboratory
Organizational Unit
Journal Issue
Series
Department
ChemistryAmes Laboratory
Abstract
Mesoporous hexagonal boron nitride (p-BN) has received significant attention over the last decade as a promising candidate for water cleaning/pollutant removal and hydrogen storage applications. Here, high-resolution solid-state NMR spectroscopy and plane-wave density-functional theory (DFT) calculations are used to obtain an atomic-level description of p-BN. 1H–15N or 1H–14N heteronuclear (HETCOR) correlation experiments recorded with either conventional NMR at room temperature or dynamic nuclear polarization surface-enhanced spectroscopy (DNP-SENS) at ca. 100 K reveal NB2H, NBH2, NBH3+ species residing on the edges of BN sheets. Ultra-high field 35.2 T 11B NMR spectroscopy was used to resolve 11B NMR signals from BN3, BN2Ox(OH)1–x (x = 0–1), BNOx(OH)2–x (x = 0–2), BOx(OH)3–x (x = 0–3), and BOx(OH)4–x– (x = 0–4). Importantly, 2D 11B dipolar double-quantum–single-quantum homonuclear correlation spectra reveal that many pore/defect sites are composed of boron oxide/hydroxide clusters connected to the BN framework through BN2O units. 1D and 2D 11B{15N} HETCOR NMR experiments, in addition to plane-wave DFT calculations of nine different structural models, further confirm the assignment of all NMR signals. The detailed structure determination of the pore and edge/defect sites within p-BN should further enable the rational design and development of next-generation p-BN-based materials. In addition, the techniques outlined here should be applicable to determine structure within other porous and/or boron-based materials.
Comments
This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Chemistry of Materials, copyright © 2022 American Chemical Society after peer review. To access the final edited and published work see DOI: 10.1021/acs.chemmater.1c03791. Posted with permission.
Description
Keywords
Carbon, Boron, Quantum mechanics, Nuclear magnetic resonance spectroscopy, Materials
Citation
DOI
Collections