Spontaneous Surface Charging and Janus Nature of the Hexagonal Boron Nitride-Water Interface.

Journal: Journal of the American Chemical Society
Published Date: Aug 6, 2025

Abstract

Boron, nitrogen, and carbon are neighbors in the periodic table and can form strikingly similar twin structures─hexagonal boron nitride (hBN) and graphene─yet nanofluidic experiments demonstrate drastically different water friction on them. We investigate this discrepancy by probing the interfacial water and atomic-scale properties of hBN using surface-specific vibrational spectroscopy, atomic-resolution atomic force microscopy (AFM), and machine learning-based molecular dynamics. Spectroscopy reveals that pristine hBN acquires significant negative charges upon contacting water at neutral pH, unlike hydrophobic graphene, leading to interfacial water alignment and stronger hydrogen bonding. AFM supports that this charging is not defect-induced. pH-dependent measurements suggest OH chemisorption and physisorption, which simulations validate as two nearly equally stable states undergoing dynamic exchange. These findings challenge the notion of hBN as chemically inert and hydrophobic, revealing its spontaneous surface charging and Janus nature, and providing molecular insights into its higher water friction compared to carbon surfaces.

Authors

  • Yongkang Wang
    College of Informatics, Huazhong Agricultural University, Wuhan 430070, China.
  • Haojian Luo
    Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.
  • Xavier R Advincula
    Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
  • Zhengpu Zhao
    International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
  • Ali Esfandiar
    Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.
  • Da Wu
    Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
  • Kara D Fong
    Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
  • Lei Gao
    Microscopy Core Facility, Biomedical Research Core Facilities, Westlake University, Hangzhou, China.
  • Arsh S Hazrah
    Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.
  • Takashi Taniguchi
    Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
  • Christoph Schran
    Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, U.K.
  • Yuki Nagata
    Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.
  • Lydéric Bocquet
    Laboratoire de Physique de l'École Normale Supérieure, Université PSL, Paris 75005, France.
  • Marie-Laure Bocquet
    Laboratoire de Physique de l'École Normale Supérieure, Université PSL, Paris 75005, France.
  • Ying Jiang
    Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China.
  • Angelos Michaelides
    Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
  • Mischa Bonn
    Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.

Keywords

No keywords available for this article.

External Resources

Popular Topics
Recent Journals