Nanoparticles in hollow carbon nanostructures

The encapsulation of preformed metal/metal oxide nanoparticles (NPs) and single molecule magnets (SMMs) into hollow carbon nanostructures (CNs) and the mechanisms underpinning their synergetic interactions are described. The properties of the encapsulated species are functions of their size, composition and structural order. Hence, developing effective strategies to build functional NP/SMM@CN nano-materials with well-organized architectures would give momentum to the commercialisation of such hybrid nanostructures, ranging from nano-electronics to nano-sized reaction vessels. The use of supercritical carbon dioxide has allowed the insertion of guest-species into CNs, and the presence of the guest-species inside CNs has been confirmed unambiguously by transition electron microscopy (TEM), which still remains the only direct method of the verification for CN filling. The interior surfaces of CNs are found to influence the thermal stability of AuNPs, controlling their metastable nature and promoting the formation of linear arrangements. The catalytic activity of AuNPs retained inside CNs has been demonstrated, with excellent selectivity towards the oxidative conversion of hydrosilane to siloxane - one of the first examples of catalytic CNs. It is shown also that magnetism of metal oxide NPs and the unique characteristics of single molecular magnets remain fully preserved inside CNs, as• assessed using superconducting quantum interference device (SQUID) magnetometry. The confinement effects and the internal structure of eNs permit subtly modulation of the orientations of the magnetic guest-species and their functional properties. Magnetoresistance measurements on SMMs encapsulated in CNs have demonstrated that the electronic properties of CNs are affected by the SMMs. This is the first indication of synergistic effects within this family of hybrid nanostructures, showing promise for future applications in nana-structured electronic and spintronic devices.EThOS - Electronic Theses Online ServiceGBUnited Kingdo