Facile fabrication of hollow hydridosilica nanoparticles with mesoporous shell and their dual effect in Pd nanoparticles immobilization

Synthesis of hollow hydridosilica nanoparticles with mesoporous shell (HMHNs) employing a mixture of cationic fluorocarbon surfactant (FC-04) and nonionic triblock copolymer surfactant (P123) as template and triethoxysilane as silica precursor is reported. It is found that the content of the FC-04 in the surfactant mixture greatly influences the aggregation state of the FC-04 and P123 surfactant template and therefore influences the morphology of the synthesized hydridosilica nanoparticles. HMHNs can be synthesized with proper amount of FC-04 surfactants due to the formation of FC-04 and P123 complex micelle, where FC-04 surfactant locates at the outer shell and the P123 constructs the inner core. Ascribed to the inherent hydride sites within the HMHNs, facile immobilization of Pd nanoparticles is achieved by using HMHNs as both the reducing agent and scaffold. The lesser processes produce some smaller Pd nanoparticles (2–3   nm) within the pore voids and relatively larger Pd nanoparticles (10–15   nm) on the outer surfaces of HMHNs. The catalytic hydrogenation of 4-nitrophenol demonstrates that the heterogeneous Pd catalyst is efficient.