Tuning d-band width for superior sodium capture in capacitive deionization
Xuexin Wang1, Baochang Cheng1, Dawei Chu2
1Key Laboratory of Fine Chemicals of College of Heilongjiang Province, College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China.
Journal of Colloid and Interface Science
|June 4, 2026
Summary
Researchers engineered sodium capture electrodes using d-band width engineering. This strategy enhances capacitive deionization (CDI) performance by optimizing ion adsorption and diffusion for efficient desalination.
Area of Science:
- Materials Science
- Electrochemistry
- Nanotechnology
Background:
- Developing efficient electrodes is crucial for advanced capacitive deionization (CDI) technologies.
- Tailoring electrode properties to optimize ion adsorption and diffusion is a key challenge.
Purpose of the Study:
- To propose and demonstrate a d-band width engineering strategy for designing superior sodium capture electrodes.
- To utilize lanthanum-doped carbon-encapsulated cobalt-iron intermetallic (La-CoFe@C) as a model system.
Main Methods:
- Engineered d-band width by doping with lanthanum to induce lattice distortion and alter metal-metal bond lengths.
- Investigated the effect of d-band width on Na+ adsorption energy, ion diffusion kinetics, and selectivity.
- Fabricated and tested the La-CoFe@C electrode for desalination performance.
Main Results:
- The La-CoFe@C electrode exhibited a widened d-band width, enhancing Na+ adsorption and ion diffusion.
- Achieved a high salt adsorption capacity of 298.9 ± 1.1 mg g⁻¹ and a rapid desalination rate of 51.4 ± 0.7 mg g⁻¹ min⁻¹.
- Demonstrated exceptional multi-ion uptake capacity and high selectivity.
Conclusions:
- D-band width engineering is a viable strategy for optimizing ion-adsorption energetics in CDI electrodes.
- The La-CoFe@C electrode shows significant promise for efficient and selective desalination.
- This work provides a generalizable framework for designing advanced electrode materials for water treatment and beyond.
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