Hierarchical Assembly of Prussian Blue Derivatives for Superior Oxygen Evolution Reaction

Abstract Prussian blue analogues (PBAs) and their derivatives with tailorable physicochemical properties are ideal functional materials for chemical sensing, energy storage, and conversion. Herein, an innovative strategy is demonstrated to prepare PBA nanoarchitectures on various metal substrates. The interfacial redox reactions between metal cyanide ions and metal substrate result in the formation of desirable PBA nanostructures via the in situ precipitation process. Furthermore, the morphology and growth rates of PBAs can be readily regulated by changing the pH value of the reaction solution. The obtained PBA nanostructures can be transformed into the corresponding metal oxides via the simple thermal treatment. More importantly, the hollow oxide derivative manifests considerable catalytic activity with a low potential of 1.53 V to achieve the benchmark current density of 10 mA cm −2 and impressive prolonged durability over 600 h. This novel synthetic approach provides a favorable pathway to synthesize binder‐free PBAs and their derivatives on diverse metal substrates, enabling new kinds of nanoarchitectures with desirable morphology and compositions for specific applications.