Amino acids functionalized vascular-like carbon fibers for efficient capacitive deionization

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Science

Background:

• Porous carbons are key for capacitive deionization (CDI) due to high surface area.
• Limitations include slow ion adsorption and poor stability from inadequate ion networks and side reactions.

Purpose of the Study:

• To synthesize and functionalize mesoporous hollow carbon fibers (HCFs) for enhanced CDI performance.
• To investigate the impact of surface modification with amino acids on desalination efficiency and stability.

Main Methods:

• Coaxial electrospinning was used to create template-assisted mesoporous hollow carbon fibers (HCFs).
• Surface modification of HCFs was achieved using arginine (HCF-Arg) and aspartic acid (HCF-Asp).
• An asymmetric CDI device was assembled using HCF-Asp and HCF-Arg electrodes.

Main Results:

• The hierarchical structure of HCFs facilitated efficient electron and ion transport.
• Amino acid functionalization suppressed co-ion repulsion and oxidative corrosion, enhancing stability.
• The asymmetric CDI device achieved a salt adsorption capacity of 45.6 mg g⁻¹, a rate of 14.0 mg g⁻¹ min⁻¹, and 80 cycles of stability.

Conclusions:

• Mesoporous hollow carbon fibers with amino acid surface modification offer a promising strategy for high-performance CDI.
• The integrated approach of structural design and surface modulation significantly boosts desalination capacity and cycling stability.