Interlayer–Surface Cooperative Dual-Site WS 2 Catalysts for Hydrogen Evolution: From DFT Screening to Interpretable Physical Descriptor Discovery

Abstract Efficient hydrogen evolution reaction (HER) electrocatalysis requires simultaneous regulation of surface adsorption chemistry and interlayer charge transport in layered materials. Here, surface substitutional doping and interlayer intercalation were combined to construct 100 TM1–TM2@WS2 (TM1, TM2 = Sc–Zn) dual-site catalysts. Density functional theory screening shows that most configurations are thermodynamically stable and that 20 systems exhibit | ΔGH* | < 0.09 eV; Fe–Ni@WS2 and Ti–Zn@WS2 reach 0.001 and −0.009 eV, respectively. In contrast, the systems with only interlayer-intercalated TM@WS2 and only surface-doped TM@WS2 still fail to reach the ideal thermoneutral adsorption range overall, providing supporting evidence for the synergistic regulation enabled by interlayer–surface coupling. The detailed results are presented in Figure S10. Charge-density-difference, Bader-charge, PDOS, and COHP analyses indicate that near-thermoneutral H* adsorption originates from coordinated electronic structure and local geometry modulation with moderate TM1–H bonding, rather than from charge transfer alone. A gradient boosting regression model achieves a test R2 of 0.963 and an RMSE of 0.068 eV. SHAP analysis and symbolic regression further yield an interpretable descriptor η integrating dB1, Rm1, and D3. These results provide a physically interpretable framework for designing non-noble-metal HER catalysts based on layered WS2.