Fig. 5. Heterobimetallic ZIF-8 nanocrystals increase in size as the Zn²⁺ atoms are substituted for Co²⁺ or Cu²⁺ atoms. Insert: highlighted data at low equivalents, where identical Co²⁺ and Cu²⁺ quantities produce different particle sizes. Particle sizes were determined by TEM (main) and SEM (insert).63,114 .