Recrystallization or Sublimation gives higher % recovery? [!]

Sublimation, because of a higher purity of resultant, compared to recrystallization which requires the addition of many things which if done wrong can live you with a higher percent of contaminant in you product.

This is entirely dependent upon the substance to be purified and the possible contaminants.

Not all substances subliminate easily. A few that do include Carbon dioxide, Iodine crystals, Caffeine, Naphthalene and para-Dichlorobenzene (both used in mothballs).

During sublimation, a solid chemical vaporizes directly into a gas which is then cooled back into a solid. The contaminates (which usually do not sublime) are left in the original location.

During recrystallization, the specimen is dissolved in a suitable solvent, which is then filtered to remove solids and then cooled to form new crystals. The contaminants as left in the liquid or the filter paper.