We have studied the morphology and structure of splintered carbon nanotubes (CNTs) grown by plasma-assisted chemical vapor deposition with the addition of hydrogen sulfide gas. Typical multi-wall CNTs are usually grown using a mixture of methane and hydrogen. The addition of hydrogen sulfide gas caused the CNTs to splinter. We call these CNTs “frilled” or “cornhusk”. Transmission electron microscopic observation showed that both the size and the length of the frill increased in accordance with the fraction of H2S gas. S was not detected from any part of the frilled CNTs by electron energy loss spectroscopy (EELS). EELS spectra indicated that the σ-bond/π-bond ratio at the split part of the frill is larger than that at the apex. These results suggest that H2S gas acts as a catalyst to form the sp3-hybridized orbital in carbon materials. We propose a possibility of controlling the morphology and structure of CNTs by adding H2S.
