The invention discloses a method for preparing a single-walled
carbon nanotube, and belongs to the technical field of single-walled carbon nanotubes. When the single-walled
carbon nanotube is prepared, the single-walled
carbon nanotube is grown by using a
chemical vapor deposition method; then, the grown single-walled carbon nanotubes are subjected to acid
pickling, then, the carbon tubes are sorted and purified by adopting a
polymer dispersant, and finally, the
polymer dispersant is removed to obtain the single-walled carbon nanotubes; the
polymer dispersant disclosed by the invention is obtained by reacting an
aldehyde-terminated fluorenyl surfactant with diamino dipyridyl; wherein the
aldehyde-terminated fluorenyl surfactant is obtained by polymerizing 9, 9-di-n-octylfluorene-2, 7-diboric acid di-
pinacol ester and
quaternary ammonium salt containing 2, 7-dibromofluorene, and then reacting with 5-formyl-2-thiopheneboronic acid
pinacol ester for end capping; the prepared single-walled carbon
nanotube is relatively high in purity and relatively high in finished product conversion rate.