The application relates to the technical field of high-purity inorganic nanomaterial preparation, and discloses a controllable preparation method of high-purity
cadmium telluride nanocrystals, which comprises the following steps: pre-dissolving a
conjugate acid salt in an aqueous
phase reaction system, introducing
ammonia as an inorganic gaseous ligand, and making a
cadmium salt precursor and a
tellurium source precursor react; the
ammonia and the
conjugate acid salt construct a pH buffer
system, transiently stabilize the generated
cadmium telluride nanocrystals in a
pH range for inhibiting
cadmium hydroxide impurities; and the
ammonia and the
conjugate acid salt are physically removed after the reaction. The application decouples the ligand stability function of the ammonia from the alkaline
side reaction of the ammonia by constructing an in-situ pH buffer
system, prevents agglomeration while inhibiting impurities, and completely removes the ligand and the salt after the reaction, so that the technical problem that
controllability and high purity cannot be achieved simultaneously in the inorganic aqueous
phase method is solved.