Cryo‐Exfoliation Synthesis of Borophene and its Application in Wearable Electronics

Abstract

Abstract Borophene, an anisotropic Dirac Xene, exhibits diverse crystallographic phases, including metallic β₁₂, χ₃, and semiconducting α phases, alongside exceptional properties such as high electronic mobility, superior Young's modulus, thermal conductivity, superconductivity, and ferroelasticity. These attributes position borophene as a promising material for energy storage, electrocatalysis, and wearable electronics. However, its widespread application is hindered by existing synthesis methods that are expensive, complex, and yield‐limited. This study presents a novel, cost‐effective, environmentally friendly cryo‐exfoliation method for borophene synthesis. Crystalline boron powder is rapidly quenched in liquid nitrogen and subjected to mild sonication, producing borophene with lateral dimensions of ≈50 to 10 µm and few‐layer thicknesses. Advanced characterizations, including Atomic Force Microscopy (AFM), High‐Resolution Transmission Electron Microscopy (HRTEM), Raman Spectroscopy, and X‐ray Photoelectron Spectroscopy (XPS), confirm structural integrity, chemical purity, and minimal surface oxidation. Molecular dynamics simulations further elucidate the weakened inter‐layer coupling induced by cryo‐processing. The integration of borophene into Polyvinylidene Fluoride (PVDF) nanocomposites demonstrates its potential for wearable electronics, achieving motion‐sensitive devices with outstanding performance, generating output voltages up to ≈40 V. This scalable cryo‐exfoliation approach paves the way for borophene‐based applications in energy harvesting, sensing, and next‐generation electronics.

Keywords

• borophene
• cryo‐exfoliation
• nanogenerator