Bridging Molecule Assisted Organic–Inorganic Interface Coassembly to Rationally Construct Metal Oxide Mesostructures

Mesostructured materials exhibit unique properties and attract great attention in many applications, but it is still challenging to synthesize mesostructured late transition metal oxides (e.g., ZnO and CuO) based on the conventional coassembly of surfactants and corresponding molecular precursors. In this work, a bridging molecule assisted coassembly strategy was developed by using ligand-capped crystalline ZnO and CuO nanocrystals (NCs) as a building block to assemble structure directing agent block copolymers (BCPs). Various mesostructured materials, including mesoporous metal oxide films and striped ellipsoidal particles, were obtained in elaborately controlled synthesis. Particularly, the structure variation under different conditions was systematically investigated by manipulating colloidal NCs–BCPs interface interactions during coassembly. Through calcination treatment to selectively decompose BCPs, a mesoporous metal oxide can be readily obtained. Taking the obtained mesoporous ZnO as an example, it exhibits excellent acetone sensing performance with high sensitivity and superior selectivity under a low working temperature (180 °C), because of the advantages of a high specific surface area (92 m2/g), rich active sites, and the unique NCs assembled framework. This bottom-up NCs–BCPs interface assembly approach can be well expanded to construct other mesostructure systems (e.g., noble metals and metal oxides–metal nanocrystal heterojunctions), serving as a universal methodology for the rational design of functional mesoporous materials with rich structural and compositional diversities.