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 MA_2Z_4 material family (M = \rm transition metal, A = \rm Si/Ge, Z = \rm N/P/As). We systematically screened structurally stable MA_2Z_4 materials for HER activity and developed activation strategies for inert variants. Six compounds (ZrSi_2N_4, ZrGe_2N_4, NbSi_2N_4, TaGe_2N_4, NbGe_2N_4, HfGe_2N_4) exhibit outstanding HER performance, characterized by near-zero hydrogen adsorption free energy and high exchange current densities. Furthermore, doping inert WGe_2N_4 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_\mathrm2p_z and H_\mathrm1s orbital hybridization in doped configurations. The work provides strategies for designing high-performance two-dimensional (2D) MA_2Z_4 HER catalysts.