Single-atom catalyst anchoring on 8-16-4-graphyne nanosheet: An efficient electrocatalyst for overall water splitting

The extension of single-atom catalysts (SACs) with high activity and stability for their application in electrochemical water splitting will be crucial for future renewable energy technology development. Here, 3d transition metal (TM) and Pt single atoms anchored on the 8-16-4 graphyne (GY) nanosheet are investigated as electrocatalysts for water splitting using density functional theory (DFT) calculations. The results reveal that single atoms of all TMs are stably anchored in the H1 site of the GY. All TM-decorated GY structures show zero band gaps that facilitate electron transfer during the electrochemical processes. Among the studied structures, C_sp and TM atoms in Co-GY with ΔGH∗ of 0.03 and 0.09 eV, respectively, and C_sp atom in Ni-GY with ΔGH∗ value of 0.07 eV show excellent HER catalytic activity. In addition, Co-GY and Ni-GY show good OER activity with an overpotential of 0.72 and 0.42 V, respectively. Therefore, it can be said that Co-GY and Ni-GY can be used as promising dual-purpose electrocatalysts for water splitting. This study shows that a single atom of inexpensive metals decorated on GY sheets can be considered for the design of high-performance and low-cost electrocatalysts for practical electrochemical applications.