Competition of single-atom Cu and Ni catalysts anchored on boron-doped graphdiyne for highly efficient oxygen evolution reaction

Abstract

As a crucial half-reaction in water splitting, the oxygen evolution reaction (OER) is significantly limited by its inherently high overpotential, which restricts the efficient production of hydrogen and oxygen. Therefore, searching for highly efficient and low-cost OER catalysts is of vital importance. Herein, based on density-functional theory calculations, we systematically investigate a series of transition metal single-atom catalysts (SACs) anchored on boron-doped graphdiyne (GDY) (TM/Bx-GDY; x = 1–6, TM = Mn, Fe, Co, Ni, Cu). The stability and OER catalytic performance of SACs are comprehensively evaluated by examining the effects of different TM atoms and boron-doping configurations. The catalytic activities of these catalysts are analyzed under two distinct OER pathways, namely conventional adsorption evolution mechanism (AEM) and *O–*O coupling mechanism (OCM). The results demonstrate that Ni/B4-GDY exhibits outstanding OER catalytic performance via the AEM pathway, achieving a remarkably low overpotential of 0.26 V, but Cu/B6-GDY shows an ultralow overpotential of 0.16 V through the OCM mechanism, while the structure–activity relationships of catalysts in OER processes are also disclosed. Besides, it is found that strong hybridization between TM-3d and O/B-2p orbitals stabilizes reaction intermediates and enhances catalytic activity. This work provides valuable insights into rational design of high-performance OER catalysts and extends the application of GDY-based catalytic materials.