Hollow Hydrangea‐Like CoRu/Co Architecture as an Excellent Electrocatalyst for Oxygen Evolution

Abstract Developing low‐cost but efficient electrocatalysts to promote the sluggish kinetics of oxygen evolution from water splitting is essential for hydrogen production. In this study, a hierarchical hollow hydrangea‐like CoRu/Co superstructure is constructed through a self‐templating method by morphology‐controlled pyrolysis of flower‐like Ru‐doped Co‐based layered double hydroxides (LDH). The anchoring of Ru into Co−LDH is the key to the formation of well‐defined hydrangea‐like three‐dimensional superstructure composed of CoRu/Co. The optimized CoRu/Co−M‐350 with a low Ru loading of 3.0 wt% exhibits excellent catalytic performances in the oxygen evolution reaction (OER) with low overpotential ( η 10 =192 mV) and excellent stability for 100 h at 100 mA cm −2 in alkaline media, outperforming the benchmark RuO 2 and most reported electrocatalysts. The superior morphology and structural features of CoRu/Co−M‐350 provide not only abundant accessible surface sites but also fast mass and electron transfer, thereby promoting OER catalysis. The present study provides a new synthetic route for preparing highly active OER electrocatalysts.