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.