Temperature effect on synthesis of different carbon nanostructures by sulfur-assisted chemical vapor deposition

The temperature effect on synthesizing different carbon nanostructures in the range of 820−1020 °C by sulfur-assisted chemical vapor deposition is investigated. When the growth temperature is no more than 900 °C (e.g. 820, 860, and 900 °C), carbon onions can be obtained, accompanying with some fishbone-like carbon nanofibers (CNFs), graphite sheet and carbon nanotubes (CNTs). When the growth temperature is increased to 940 °C or above (e.g. 980 and 1020 °C), the products are mainly CNTs. Furthermore, by comparing the nitrogen adsorption-desorption results of samples obtained with and without sulfur addition at each temperature, it is found that the specific surface area (SSA) of products can be remarkably enlarged after introducing small amount of sulfur during growth. This is favorable to their applications in areas like electrodes of supercapacitors, adsorbents, catalyst supports, and so on.