Boron Nitride Nanoporous Membranes with High Surface Charge by Atomic Layer Deposition

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Atomic layer deposition (ALD) offers precise control over thin film growth.
• Boron nitride (BN) is a promising material for membrane applications due to its chemical inertness and tunable properties.
• Nanoporous membranes are crucial for separation and energy applications.

Purpose of the Study:

• To design and fine-tune boron nitride (BN) single nanopores and nanoporous membranes using ALD.
• To investigate the impact of BN film thickness on nanopore diameter and ionic transport.
• To explore the potential of ALD-fabricated BN membranes for various applications.

Main Methods:

• Development of a novel ALD process using BBr3 and NH3 precursors for BN thin film synthesis.
• Characterization of BN films for thickness, composition, and microstructure.
• Fabrication of BN nanoporous membranes on anodic aluminum oxide templates.
• Ionic transport measurements and molecular dynamics simulations.

Main Results:

• Successful synthesis and characterization of conformal BN thin films via ALD.
• Demonstration of tunable single nanopore diameters by controlling BN thickness.
• Estimation of surface charge density at pH 7 (0.16 C·m⁻² without slip, 0.07 C·m⁻² with 3 nm slip).
• Validation of experimental results through molecular dynamics simulations.

Conclusions:

• ALD is a scalable and effective method for fabricating tunable BN nanoporous membranes.
• The developed BN nanoporous membranes exhibit high ion transport properties.
• These membranes show significant potential for applications in ionic separation, energy harvesting, and ultrafiltration.