Growth of Cu-BTC MOFs on dendrimer-like porous silica nanospheres for the catalytic aerobic epoxidation of olefins

Abstract

The composition of metal–organic frameworks (MOFs) and porous carriers can be utilized for a variety of material applications. In this study, DPSNs@Cu-BTC nanocomposites are achieved utilizing Dendrimer-like Porous Silica Nanoparticles (DPSNs) as the support through a template-mediated self-assembly mechanism. The fabrication process is initiated from the controllable growth of Cu₂O nanoparticles (NPs) in the center-radial porous channels of DPSNs, which forms DPSNs@Cu₂O nanocomposites. Under the protection of DPSNs, the loaded Cu₂O NPs gradually dissolved in the weak acid solution, thus providing copper ions to guide the formation and growth of Cu-BTC nanocrystals. Moreover, the Cu-BTC NPs were restricted in the center-radial porous channels of the DPSNs, thus resulting in small sizes and a uniform distribution. The formation of the DPSNs@Cu-BTC nanocomposites with adjustable amounts of Cu-BTC mainly depended on the amounts of Cu₂O NPs loaded and the amount of organic ligands added. Furthermore, the nanocomposite exhibited high catalytic performance and good recyclability taking advantage of the uniform loading of small-sized Cu-BTC NPs in the accessible center-radial porous channels of the DPSNs. This new design of DPSNs@Cu-BTC provided a new approach for the synthesis of various MOF-based nanocomposites with improved performance.