Scalable Production of Few-Layer Boron Sheets by Liquid-Phase Exfoliation and Their Superior Supercapacitive Performance

Abstract

Although two-dimensional boron (B) has attracted much attention in electronics and optoelectronics due to its unique physical and chemical properties, in-depth investigations and applications have been limited by the current synthesis techniques. Herein, we demonstrate that high-quality few-layer B sheets can be prepared in large quantities by sonication-assisted liquid-phase exfoliation. By simply varying the exfoliating solvent types and centrifugation speeds, the lateral size and thickness of the exfoliated B sheets can be controllably tuned. Additionally, the exfoliated few-layer B sheets exhibit excellent stability and outstanding dispersion in organic solvents without aggregates for more than 50 days under ambient conditions, owing to the presence of a solvent residue shell on the B sheet surface that provides excellent protection against air oxidation. Moreover, we also demonstrate the use of the exfoliated few-layer B sheets for high-performance supercapacitor electrode materials. This as-prepared device exhibits impressive electrochemical performance with a wide potential window of up to 3.0 V, excellent energy density as high as 46.1 Wh/kg at a power density of 478.5 W/kg, and excellent cycling stability with 88.7% retention of the initial specific capacitance after 6000 cycles. This current work not only demonstrates an effective strategy for the synthesis of the few-layer B sheets in a controlled manner but also makes the resulting materials promising for next-generation optoelectronics and energy storage applications.

A MXene‐Coated Activated Carbon Cloth for Flexible Solid‐State Supercapacitor

“…Figure b shows the Nyquist diagram of HHK‐CC@Ti 3 C 2 T X ‐X as the electrode material. The EIS curve of HHK‐CC@Ti 3 C 2 T X ‐3 is close to vertical in the low‐frequency region, which indicates good diffusion performance, and it maintains high capacitance retention rate under large current. However, the diffusion performance of HHK‐CC@Ti 3 C 2 T X ‐4 can be seen deteriorated significantly.…”

Boron Nanosheets for Efficient All‐Optical Modulation and Logic Operation

“…Here, sonication‐assisted liquid‐exfoliation method was employed to exfoliate boron nanosheets in isopropanol alcohol (IPA). The details can be found in the Supporting Information, which is adopted from a previous literature with slight modifications . As shown in Figure a,b, nanosheets with lateral size ranging from tens to hundreds of nanometers (concentrate in the range of 100–200 nm, also can be confirmed by following atomic force microscope (AFM) characterizations) were obtained, which indicate the exfoliation of bulk boron (size of ≈20 µm).…”

Review of borophene and its potential applications

“…This is equivalent to a hydrogen storage capacity of 10.7 wt %, which is much higher than that of Li-decorated silicene (6.3 wt %) and MoS2 (4.8 wt %). In Few-layer boron sheets exhibit excellent performance as supercapacitor materials [103]. This experimental study not only shows us that few layer boron sheets can be synthesized in a controlled manner but also broadens the practical application prospect of boron sheets.…”

“…Superconductivity properties of borophene have been reported in various studies[29,54,61,[101][102][103][104][105][106]. Zhao et al carried out a systematic study of borophene with a range of boron vacancy concentration[61].…”