Synthesis and raman response of multiwalled-carbon nanotubes decorated with gold nanobowls prepared via galvanic replacement of silver nanoparticles

Gold nanobowls (AuNBs) of ~5 nm in diameter grown on multiwalled carbon nanotubes (MWCNT) were successfully synthesized via galvanic replacement of silver nanoparticles (AgNPs). A 3-fold Raman signal enhancement of MWCNT was observed when Au replacement with Ag approached to completion. Moreover, AuNBs can be readily released from CNT surface via sonication with 1-octanethiol (OT). Our current method demonstrates a novel technique on producing smallest dimension of AuNBs so far simply achieved in wet chemical process.