Document Type

Article

Publication Date

6-15-2025

Department

Department of Physics

Abstract

In this work, we systematically investigated the hydrogen storage properties of multilayer Ti3C2Tx MXene using density functional theory (DFT) coupled with the quantum-thermodynamic model to include the thermodynamic effect on hydrogen adsorption and storage behavior over a wide range of applied pressure and temperature. In addition to the surface-adsorbed hydrogen, we show that the interlayer spacing is a plausible storage route that could contribute to an additional hydrogen storage capacity. Due to hydrogen-bond bounded multilayer Ti3C2Tx, the insertion, diffusion, and adsorption of hydrogen molecules into the interlayer spacing of the multilayer structure require sufficient external pressure to overcome the energy penalty to separate the multilayer structure. Using DFT calculations, we presented a novel model in attempt to unveil the mechanism of the nanopump effect, and providing new insights into its underlying process from a theoretical perspective. The calculated upper bound of theoretical gravimetric storage capacity using DFT calculation for multilayer Ti3C2Tx is ∼3.8 wt% H2. While at 77 and 300 K with external pressure of 25 MPa, the predicted gravimetric capacity employing the DFT and quantum-thermodynamic model are found to be ∼2.1 and 0.67 wt% H2, respectively, and experimentally, these H2-stored multilayer Ti3C2Tx structures can be verified based on our simulated XRD analysis. Based on this work, we believe that our current simulation model can provide a reasonable and realistic prediction of hydrogen storage capacity and a systematic study of hydrogen storage mechanisms in other two-dimensional (2D) layered materials, besides multilayer Ti3C2Tx.

Publisher's Statement

© 2025 The Authors. Published by Elsevier Ltd. Publisher’s version of record: https://doi.org/10.1016/j.est.2025.116577

Publication Title

Journal of Energy Storage

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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