Publications

The corrosion behavior of zirconium alloys for nuclear applications is closely correlated with second phase particles. This study systematically investigates the dissolution, diffusion, and clustering behavior of hydrogen and oxygen atoms in C15 ZrCr2 and ZrFe2 Laves phases using first-principles calculations. Our findings reveal that H preferentially occupy tetrahedral interstitial sites, whereas O exhibit stronger affinity for hexahedral interstitial positions. Compared to ZrCr2, ZrFe2 inhibits the dissolution of impurity atoms. A comprehensive diffusion network of interstitial impurity atoms in the C15 phase is constructed, where both H and O atoms favor intra-ring diffusion over inter-ring diffusion. Moreover, metal vacancies in the C15 phase substantially increase the binding energy of impurity clusters, serving as preferential nucleation sites for hydride and oxide precipitation.

• Machine learning predicts HCP interstitial energies with R 2 = 0.951 validation. • SHAP analysis identifies weighted solid angle as key stability descriptor. • SISSO derives simple linear equation for interstitial-substitutional interactions. • Atomic radius differences dominantly decide stability and formation energy. Interactions between non-metal interstitial atoms and substitutional elements in HCP metals critically affect material properties, yet existing predictive models lack systematic integration of these effects. This study develops a data-driven framework to accurately predict formation energy and stability while elucidating their underlying mechanisms. We integrated density functional theory (DFT) calculations with machine learning (ML) techniques to investigate non-metal interstitials in HCP metals containing substitutional elements. We constructed an automatically procedure to label the stability of interstice which is very important for constructing dataset. The dataset comprised DFT-derived formation energies (for prediction), labeled stability of non-metal interstitial atoms (for classification), and VoronoiNN-extracted geometric and elemental descriptors. Various ML algorithms were trained, with SHAP and SISSO analyses identifying key features and yielding a predictive equation, subsequently validated on an independent dataset. The linear equation demonstrated strong generalization capability (R 2 = 0.951 on validation). Atomic radius differences and electronegativity emerged as critical descriptors, highlighting distinct interstitial behaviors in HCP structures. This research delivers an efficient predictive tool that reduces reliance on computationally expensive DFT calculations and accelerates alloy defect investigation. By addressing the gap in systematic interstitial-substitutional interaction models in HCP metals, this work enhances understanding of defect energetics and establishes a foundation for applications across broader crystal systems.

The corrosion of Zircaloy fuel cladding is one of the crucial issues during the operation of pressurized water reactors (PWR). In this work, a Zr-Nb-H-O reactive force field (ReaxFF) is constructed to study the corrosion mechanisms and irradiation effect of Zr-Nb alloys at the atomic landscape. This ReaxFF can describe the interactions between water dissociation products and Zr-Nb alloys, and the stability as well as diffusion properties of irradiation defects in Zr bulk. The molecular dynamics (MD) simulations based on the present ReaxFF show that Nb can thicken the suboxide layer during the corrosion process, as well as the promotion effect of irradiation on corrosion varies under different PKA (Primary Knock-on Atom) energies. The ReaxFF described here has the potential to be a new tool for understanding the in-reactor corrosion mechanism under the irradiation environment.

Both the sluggish sulfur redox reaction (SRR) kinetics and lithium polysulfides (LiPSs) shuttle effect limit the practical application of Li‐S batteries. Designing heterostructure sulfur hosts has emerged as an effective way to address these two issues with one material. However, the principles of heterostructures reinforced Li‐S batteries remain inadequately understood. Here, it is demonstrated for the first time that increasing the entropy of heterostructure can promote its SRR catalytic activity and alleviate the LiPSs shuttling. By a simple solution‐based strategy, a highly chaotic MXene‐based heterostructure (HCMH, TiS 2 /TiN/TiO 2 /Ti 3 C 2 T x ) is fabricated. The smart integration of “high entropy”, heterostructure, and MXene endow the HCMH catalyst with significantly improved performance, demonstrated by a much smaller Tafel slope of 62.9 mV dec −1 and a higher electron transfer number of 7.10, compared with the moderately chaotic MXene‐based heterostructure (MCMH, TiO 2 /TiN/Ti 3 C 2 T x ) and MXene. DFT theoretical calculations reveal that introducing new phases lowers the Gibbs energy barriers of both rate‐limiting Li 2 S 2 /Li 2 S reduction and Li 2 S decomposition. Upon the addition of only 5 wt.% HCMH to the sulfur cathode, both the reversible capacity and rate capability of Li‐S cells are greatly improved, which further highlights the importance of the high entropy “cocktail effect” in the design of SRR electrocatalysts in the future.

Zirconium alloys, being crucial materials in the nuclear industry, frequently encounter issues related to oxidative corrosion. Understanding the interaction between O atom and alloying atoms at the atomistic scale is helpful for optimizing Zr alloys with improved corrosion resistance. In the present study, a first-principles approach is used to understand the stability and diffusion properties of an O atom in α -Zr with different alloy atoms (Sn, Nb, Fe and Cr). Our findings reveal that the most stable position for oxygen is always the octahedral (Oct) site whether it coordinates with an alloy atom or not. Comparing to other alloy atoms, Fe tends to exclude interstitial O even at the long range and the interaction is stronger than others, while the long-range interaction of Nb is the weakest. All alloy atoms considered in this work can enhance interstitial O diffusion rate, and promote the anisotropy of O diffusion. This work also confirms that the kinetically resolved activation method is a reliable method to predict the O diffusion barrier in α -Zr.