Interlayer Covalent Reinforcement-Enabled Lattice Reprogramming for Durable Capacitive Deionization

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Engineering

Background:

• Capacitive deionization (CDI) is a promising low-energy desalination method.
• Current CDI electrodes, including molybdenum sulfide (MoS2), face challenges with ion storage capacity and long-term durability.
• There is a critical need for advanced electrode materials to improve CDI efficiency and stability.

Purpose of the Study:

• To develop a high-performance electrode material for capacitive deionization (CDI).
• To enhance the ion storage capacity and stability of molybdenum sulfide (MoS2) electrodes.
• To establish a generalizable strategy for improving two-dimensional (2D) materials in CDI applications.

Main Methods:

• Developed a covalent interlayer engineering strategy for layered molybdenum sulfide (MoS2).
• Intercalated butane-1,4-diol to form rigid covalent linkages and expand interlayer spacing.
• Induced local 2H-to-1T lattice reconstruction in MoS2 structure.

Main Results:

• Achieved an ultrahigh salt removal capacity of 77.4 mg g⁻¹, over threefold higher than pristine MoS2.
• Demonstrated exceptional electrode stability with no measurable decay over 50 cycles.
• Engineered MoS2 outperformed state-of-the-art 2D electrodes in scalable brine treatment.

Conclusions:

• Covalently supported interlayer engineering transforms MoS2 into a high-capacity, stable CDI electrode.
• The strategy resolves the performance-stability paradox in CDI, advancing practical desalination.
• This approach provides a generalized paradigm for reinforcing 2D materials for energy and environmental applications.