December 1 - 6, 2024
Boston, Massachusetts
Symposium Supporters
2024 MRS Fall Meeting & Exhibit
EL06.10.03

Single-Ion Spectroscopy of h-BN Point Defect Fluorescence in Liquid Environments

When and Where

Dec 6, 2024
2:15pm - 2:30pm
Hynes, Level 1, Room 104

Presenter(s)

Co-Author(s)

Yecun Wu1,Kun Xu1,Hori Sarker2,Takashi Taniguchi3,Kenji Watanabe3,Frank Abild-Pedersen2,Arun Majumdar1,Yan-Kai Tzeng2,Steven Chu1

Stanford University1,SLAC National Accelerator Laboratory2,National Institute for Materials Science3

Abstract

Yecun Wu1,Kun Xu1,Hori Sarker2,Takashi Taniguchi3,Kenji Watanabe3,Frank Abild-Pedersen2,Arun Majumdar1,Yan-Kai Tzeng2,Steven Chu1

Stanford University1,SLAC National Accelerator Laboratory2,National Institute for Materials Science3
Understanding individual ions in solutions is essential for advancing our knowledge of complex chemical systems. However, tracking and detecting ions at the single-ion level in liquid environments remains a challenge. We introduce a strategy for visualization and differentiation of different ions in liquid environment via point defects in hexagonal boron nitride (h-BN) as the ion sensor. Ions interacting with the optically active point defects in h-BN alter emission properties, allowing us to capture these changes and visualize single ions. Using Li<sup>+</sup> in organic electrolytes as a model, we observed a spectral shift of over 10 nm upon Li<sup>+</sup> addition, and an over 50 nm red shift with applied electric fields due to reactions between Li<sup>+</sup> and h-BN point defects. Frequency domain analysis further revealed the rapid dynamics of ion migration and the slow electrochemical reactions. We further spectroscopically differentiated various ions (H<sup>+</sup>, Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>, Zn<sup>2+</sup>, Al<sup>3+</sup>) in aqueous solution. Each ion, with its distinct electron cloud configuration, interacts distinctively with the electron clouds of h-BN defects, resulting in specific and identifiable spectroscopic signatures. This ion sensing platform enables the direct visualization and differentiation of individual ions in a liquid environment, offering insights into chemical reactions at the single-ion level. This capability presents potential applications in various fields involving ions in liquids, including but not limited to biology, battery technology, and environmental science.

Keywords

2D materials | defects

Symposium Organizers

Qiushi Guo, City University of New York
Doron Naveh, Bar-Ilan University
Miriam Vitiello, Consiglio Nazionale delle Ricerche
Wenjuan Zhu, The University of Illinois at Urbana-Champaign

Symposium Support

Silver
Montana Instruments

Bronze
Oxford Instruments

Session Chairs

Souvik Biswas
Chiara Trovatello

In this Session