An Efficient Turing‐Type Ag2Se‐CoSe2 Multi‐Interfacial Oxygen‐Evolving Electrocatalyst**

Abstract Although the Turing structures, or stationary reaction‐diffusion patterns, have received increasing attention in biology and chemistry, making such unusual patterns on inorganic solids is fundamentally challenging. We report a simple cation exchange approach to produce Turing‐type Ag 2 Se on CoSe 2 nanobelts relied on diffusion‐driven instability. The resultant Turing‐type Ag 2 Se‐CoSe 2 material is highly effective to catalyze the oxygen evolution reaction (OER) in alkaline electrolytes with an 84.5 % anodic energy efficiency. Electrochemical measurements show that the intrinsic OER activity correlates linearly with the length of Ag 2 Se‐CoSe 2 interfaces, determining that such Turing‐type interfaces are more active sites for OER. Combing X‐ray absorption and computational simulations, we ascribe the excellent OER performance to the optimized adsorption energies for critical oxygen‐containing intermediates at the unconventional interfaces.