Confined organometallic Au1N x single-site as an efficient bifunctional oxygen electrocatalyst

Highlights: • A new-type organometallic Au₁N_x single-site is designed to realize highly efficient and durable bifunctional oxygen electrocatalytic performance. • The atomic Au₁N_x single-sites achieve extremely large mass activity of ~9000 and ~1500 A∙g_Au⁻¹ for oxygen reduction and evolution reaction, respectively, 20–26 times higher than those of benchmarking Pt/C and RuO₂ electrocatalyst. • A facile and ecofriendly "amine-induced reduction" strategy was developed to large-scale construct the atomically dispersed Au₁N_x single sites. • The combination of strong Au–N interaction and robust coupling effect between Au₁N_x and carbon-nitride endows the atomic Au₁N_x single-site with excellent redox catalytic activity and long-term durability for oxygen-involved catalysis. The development of organometallic complexes with abundant stable single-atom active sites is highly desirable for cost-effective and commercial electrocatalysis towards renewable energy conversion and storage. Here, we report an atomic-level design and construction of a new type of organometallic Au₁N_x single-site confined on organic carbon-nitride support as a promising bifunctional electrocatalyst for efficient and durable oxygen reduction (ORR) and evolution reaction (OER) performance. The combination of atomic characterizations and theoretical calculations confirm that the atomically dispersed Au¹⁺ atoms are grafted onto carbon-nitride support by covalent Au–N bonds via an amine-induced-reduction strategy, forming atomic Au₁N_x single-sites with potential oxygen-related catalytic activity. Hence, this developed Au₁N_x single-site electrocatalyst could exhibit excellent electrocatalytic activity and durability with extraordinarily large mass activities of ~9000 A• g_Au⁻¹ for ORR at the half-wave potential 0.76 V, and of ~1500 A• g_Au⁻¹ for OER at overpotential 0.45 V, 20–26 times higher than those of benchmarking Pt/C and RuO₂ electrocatalysts.