Formation of hollow carbon nanoshells from thiol stabilised silver nanoparticles via heat treatment

• Published in: Carbon (New York) Vol. 139; pp. 538 - 544
• Main Authors: Watts, Julie A., Fay, Mike W., Rance, Graham A., Brown, Paul D., Khlobystov, Andrei N.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.11.2018; Elsevier BV
• Subjects: Alkanes; Carbon; Carbon nanotubes; Heat treating; Heat treatment; Heating rate; Nanomaterials; Nanoparticles; Silver; Temperature effects; Thermal transformations
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2018.06.074

Uniform, < 10 nm sized, hollow carbon nano-shells (HCNS) have been prepared via a single-step, thermal treatment of alkanethiol stabilised Ag nanoparticles (TS-AgNP). Direct evidence for the formation of spherical HCNS from TS-AgNP is provided by in situ MEMS heating on Si3N4 supports within a TEM, and ex situ thermal processing of TS-AgNP on carbon nanotube supports. A mechanism is proposed for the thermally driven, templated formation of HCNS from the TS-AgNP stabilising layer, with Ag catalysing the graphitisation of carbon in advance of thermally induced AgNP template removal. This facile processing route provides for excellent size control of the HCNS product via appropriate AgNP template selection. However, a rapid rate of heating was found to be crucial for the formation of well-defined HCNS, whilst a slow heating rate gave a much more disrupted product, comprising predominantly lacy carbon with decreased levels of graphitic ordering, reflecting a competition between the thermal transformation of the TS-layer and the rate of removal of the AgNP template. Bright field, diffraction contrast TEM micrographs of (a) TS-AgNP/Si3N4 before rapid in situ heating to 850 °C (TP-1); and (b) the resultant HCNS, imaged at 850 °C. [Display omitted]