Transition metal nanocrystals (TMNs) find extensive applications across a diverse range of catalytic reactions. Among these, single-crystal TMNs, characterized by their highly ordered atomic structure, are frequently employed as model catalysts for fundamental electrocatalytic mechanism investigations. In contrast, polycrystalline TMNs, which contain numerous grain boundaries, are predominantly utilized to delve into the correlation between defects and catalytic activity. Presently, the synthesis of both single-crystal and polycrystalline TMNs (MC/PC-TMNs) necessitates meticulous control over external experimental parameters, such as concentration and temperature, rendering the process intricate and time-consuming. Moreover, pinpointing the precise parameter values essential for fabricating single-crystal or polycrystalline structures proves challenging, thereby complicating morphological control. Consequently, there arises a pressing need to devise a method that hinges on intrinsic material parameters, rather than experimental conditions, to facilitate the synthesis of MC/PC-TMNs.