Construction of Single-Crystalline Prussian Blue Analog Hollow Nanostructures with Tailorable Topologies

Engineering complex nanostructures, particularly topologically intricate architectures, represents an appealing challenge for chemists and material scientists because such structures often manifest unique properties. Here, we demonstrate the versatility of a self-templated epitaxial growth strategy for construction of single-crystalline hollow nanostructured Prussian blue analogs (PBAs). Specifically, this strategy enables a controllable synthesis of Co-Fe PBA cages, frames, and boxes with diverse geometries by tuning their growth kinetics and thus expands the richness of their topological complexity. As an attempt, the topologies of these structures are identified and discussed. After thermal treatment, the corresponding oxide derivatives with preserved structures exhibit enhanced electrocatalytic activity for the oxygen evolution reaction in alkaline medium, where the frame structures demonstrate the best catalytic performance. Our work may further advance the topology in chemistry and materials science for realizing not only the geometries of the nanostructures but also their topology-dependent catalytic properties.