  This article describes base-line data used in conjunction with the Materials
Today Chemistry article: The green synthesis of exceptional braided, helical
carbon nanotubes and nano spiral platelets made directly from CO$_2$. The data
includes Raman, XRD, SEM, TEM, EDX and high contrast TEM of conventional carbon
nanotubes (CNTs) synthesized from carbon dioxide electrolytic splitting in
molten electrolyte for comparison to synthesized helical carbon nanotubes grown
in the main article. This data article also presents SEM showing that
uncontrolled electrolytic CO$_2$ splitting leads to bent and deformed CNTs,
rather than straight or helical CNTs, and SEM that helical carbon nanotubes and
helical carbon nanoplatelets can be produced with only partial control of the
electrolysis current and with no defect inducing agents. A novel, cheap
synthesis of high purity helical nanocarbon is discovered. A baseline and
comparative experimental data for non-helical analogues is presented. Both the
non-helical and helical nanocarbon are synthesized from the greenhouse gas
CO$_2$ by molten carbonate electrolysis.
