“Remote” Fabrication via Three‐Dimensional Reaction‐Diffusion: Making Complex Core‐and‐Shell Particles and Assembling Them into Open‐Lattice Crystals

Reaction-diffusion (RD) processes initiated from the surfaces of mesoscopic particles can fabricate complex core-and-shell structures. The propagation of a sharp RD front selectively removes metal colloids or nanoparticles from the supporting gel or polymer matrix. Once fabricated, the core structures can be processed “remotely” via galvanic replacement reactions, and the composite particles can be assembled into open-lattice crystals.