Design a Functional Graphene with Decoration of Dual Transition Metal Dopants for Hydrogen Evolution Electrocatalysis

Since hydrogen is a promising alternative to fossil fuels due to its high energy density and environmental friendliness, water electrolysis for hydrogen production has received widespread attentions wherein the development of active and stable catalytic materials is a key research direction. This article designs a dual transition metal doped functional graphene for hydrogen evolution reaction via density functional theory calculations. Among varied combinations, 16 candidates are screened out that are expected to be stable as reflected by the criterion of formation energy E_f<0 and active due to its free energy of hydrogen adsorption ▵G_H within the window of ±0.3 eV. Considering its feasibility in structural modification and electronic adjustment due to the strong dd orbital couplings, the homogeneous dual-atom moiety delivers improved performance toward hydrogen evolution in comparison with the single-atom counterpart. Owing to the good resistance of electrochemical dissolution, the work figures out the potential combinations of Cu₂C₃N₃, Rh₂C₆, Rh₂C₃N₃ and Rh₂N₆ endowed with the ▵G_H values of -0.03, 0.12, -0.21, and 0.06 eV, respectively, being comparable to the benchmark Pt materials. Therefore, this study provides a new direction for the experimental synthesis of highly active carbon-based electrocatalysts and highlights the well-tuning ability posed by the dual-atom interaction.