Control of carbon helix fiber formation and fiber composition over Cu/SrO catalyst mixtures

• Synthesis of carbon nanofibres from acetylene over CuO/SrO catalysts with different Cu/Sr ratios.
• The SrO in the Cu/Sr mixtures controls the Cu particles sizes and hence the CNF linear/helix ratio.
• Presence of the SrO modifies the chemical nature of the CNFs.

CuO and CuO/SrO catalysts with different Cu/Sr ratios were prepared by a co-precipitation method and calcined at 350 °C. Carbon nanofibers (CNFs) were grown over the reduced catalysts by chemical vapor deposition (acetylene/H2, 300 °C, 30 min). The TEM images of the CNFs revealed a mixture of straight and coiled CNFs with a broad diameter distribution (50–400 nm) dependent on the Cu/Sr ratio of the catalyst used. The as-prepared CNFs were characterized by TEM, XRD and Raman spectroscopy and the data revealed the highly amorphous nature of the CNFs. IR and TGA analysis revealed that the chemical composition of the CNFs changed as the SrO content changed. The SrO content also affected the Cu particle size and influenced the morphology of the Cu particles from which the CNFs grew.

TEM pictures of carbon nanofibers grown over [A] CuO; and CuO/SrO catalysts with different Cu/Sr ratio of [B] 3.2 [C] 1.2 and [D] 1.Figure optionsDownload as PowerPoint slide