Preparation and characterisation of novel “sea-cucumber”-like structures containing carbon and boron Original Research Article

Spray-pyrolysis of a ferrocene–xylene–triethylborane mixture at 900 °C results in a novel “sea-cucumber”-like structure containing carbon and boron. SEM studies show that these structures are hollow with diameter between 100 and 500 nm and lengths varying from 30 to 40 μm. HRTEM and EELS studies reveal that the hollow structures are partly filled with iron. They are formed by a more graphitic internal core, which hardly contains any B. This core is coated by a more disordered B-containing C material. The amount of B in this coating is around 3 at.%. In addition, at this pyrolysis temperature, the growth of open-ended tubular nanostructures (30–40 nm diameter; 100–200 nm length) on the surface of the sea-cucumber-like structure is observed. These tubular nanostructures are not very graphitic and exhibit a similar composition to the coating of the sea-cucumber-like structure (around 3 at.% of B). The study of material produced at different pyrolysis temperatures show that the growth of these tubular nanostructures and the boron content are temperature dependent. Finally, preliminary results corresponding to oxidation resistance studies are presented.