Superior Oxygen Evolution Electrocatalyst based on Ni‐Ellagic Acid Coordination Polymer

The oxygen evolution reaction (OER) is central to energy conversion technologies, but the high cost and scarcity of commercial noble metal catalysts limit their widespread application. Natural products exhibit great potential in preparing high‐performance electrocatalysts due to their cost‐effectiveness and sustainability. Here, a kind of 1D polymers [M‐EA (M═Co, Cu, Ni)] for oxygen evolution reaction via the complexation of ellagic acid (EA) with metal ions are reported. It is found that Ni‐EA displays a low overpotential (190 mV at 10 mA cm−2) and an ultralow Tafel slope (28 mV dec−1), with a production cost of only 3.6 × 10−2% of IrO2. Density functional theory investigations reveal the electrocatalytic mechanism of the OER. A rechargeable Zn‐Air battery using Ni‐EA+Pt/C as the air electrode shows a lower charging potential and better cycling stability than the IrO2+Pt/C‐based battery. This work provides a train for the development of state‐of‐the‐art OER catalysts. This work reports a kind of 1D coordination polymers based on nonprecious metals and natural products, which show an impressive overpotential of 190 mV at 10 mA cm−2 and an ultralow Tafel slope of 28 mV dec−1. The inexpensive and sustainable raw materials can reduce the OER catalyst cost by 4 orders of magnitude.