Screening and activation of two-dimensional MA₂Z₄ for hydrogen evolution reaction: A first-principles study

Developing efficient and low-cost catalysts for the hydrogen evolution reaction (HER) is crucial for sustainable hydrogen production. This study focuses on the novel two-dimensional MA₂Z₄ material family (M = transition metal, A = Si/Ge, Z = N/P/As). We systematically screened structurally stable MA₂Z₄ materials for HER activity and developed activation strategies for inert variants. Six compounds (ZrSi₂N₄, ZrGe₂N₄, NbSi₂N₄, TaGe₂N₄, NbGe₂N₄, HfGe₂N₄) exhibit outstanding HER performance, characterized by near-zero hydrogen adsorption free energy and high exchange current densities. Furthermore, doping inert WGe₂N₄ with specific elements (e.g., Ru, Re, Hf, Cu) effectively activates its HER performance. This enhancement stems from strengthened N–H bonding due to N_2pz and H_1s orbital hybridization in doped configurations. The work provides strategies for designing high-performance two-dimensional (2D) MA₂Z₄ HER catalysts.