Multi-active sites derived from a single/double perovskite hybrid for highly efficient water oxidation

The oxygen evolution reaction (OER) plays a crucial role in the application of water splitting, which is a highly competitive option for a sustainable energy future. Thus, it is vital to design highly active and durable electrocatalyst for OER. Herein a hybrid with the nominal composition of Ba ₂ Co _1.5 Mo _0.25 Nb _0.25 O _6-δ (denoted as BC1.5 MN) electrocatalyst consisting of both double perovskite and single perovskite structures is synthesized by a solid-state reaction method. When tested as an electrocatalyst for OER, the BC1.5 MN electrocatalyst requires a current density of 10 mA cm ⁻² at an overpotential of 400 mV, an onset overpotential of 260 mV, and a Tafel slope of 70 mV dec ⁻¹ , which are superior to that of precious metal oxide IrO ₂ catalyst. Chronoamperometric and cyclic voltammetry studies demonstrate that the BC1.5 MN electrocatalyst has outstanding durability in alkaline solution. The synergistic effect between multi-active sites derived from a single/double perovskite hybrid structure results in one of the most active perovskite-based OER electrocatalysts in alkaline solution.