A Rational Biomimetic Approach to Structure Defect Generation in Colloidal Nanocrystals
University of California - Los Angeles Los Angeles United States
Pagination or Media Count:
Controlling the morphology of nanocrystals NCs is of paramount importance for both fundamental studies and practical applications.The morphology of NCs is determined by the seed structure and the following facet growth. While means for directing facet formation in NC growth have been extensively studied, rational strategies for the production of NCs bearing structure defects in seeds have been much less explored. Here, we report mechanistic investigations of high density twin formation induced by specificpeptides in platinum Pt NC growth, on the basis of which we derive principles that can serve as guidelines for the rational design of molecular surfactants to introduce high yield twinning in noble metal NC syntheses. Two synergistic factors are identified in producing twinned Pt NCs with the peptide 1 the altered reduction kinetics and crystal growth pathway as a result of the complex formation between the histidine residue on the peptide and Pt ions, and 2 the preferential stabilization of 111 planes upon the formation of twinned seeds. We further apply the discovered principles to the design of smallorganic molecules bearing similar binding motifs as ligandssurfactants to create single and multiple twinned Pd andRh NCs. Our studies demonstrate the rich information derived from biomimetic synthesis and the broad applicability of biomimetic principles to NC synthesis for diverse property tailoring.