Breaking HER limits with Ni@B₄₀’s single-atom catalytic prowess

The hydrogen evolution reaction (HER) has emerged as a key process in the pursuit of sustainable alternatives to nonrenewable fuels. Single-atom catalysts (SACs) are particularly promising for HER electrocatalysis due to their exceptional atom utilization, high electrical conductivity, and thermal stability. In this study, we systematically evaluated the catalytic potential of late first-row transition metal-decorated TM@B₄₀ (TM = Zn, Fe, Co, Cu, and Ni) complexes as SACs for HER using density functional theory (DFT) and ab initio molecular dynamic (AIMD) calculations. The interaction energies (E_int of these complexes ranged from − 1.16 to -3.72 eV at B3LYP-D3/6–31 + G (d) method in aqueous phase, confirming their thermodynamic stability. Notably, Ni@B₄₀ and Cu@B₄₀ exhibited the lowest Gibb’s free energy of -0.01 eV and 0.01 eV, respectively, identifying them as the most efficient HER catalysts. The H-Ni@B₄₀ and H-Cu@B₄₀ complexes further demonstrated a favorable hydrogen adsorption energy (ΔE_H*) of -0.29 eV and − 0.25 eV, reinforcing their stability. Density of states (DOS) analysis revealed the formation of new energy states upon hydrogen adsorption, facilitating charge transfer between Ni@B₄₀ and H, in agreement with frontier molecular orbital (FMO) analysis. These findings underscore the potential of TM@B₄₀ complexes as highly efficient SACs for HER, offering a viable strategy for designing cost-effective and high-performance electrocatalysts for hydrogen production.