物理化学学报2020，Vol.36Issue(9)：147-152,6.DOI:10.3866/PKU.WHXB201908041
金二元纳米晶超晶格的自组装和结构表征
Self-Assembly and Structural Characterization of Au Binary Nanocrystal Superlattices
摘要
Abstract
The assembly of twocomponent nanocrystals (NCs) such as metals,magnets,and semiconductors into binary nanocrystal superlattices (BNSLs) provides a fabrication route to novel classes of materials.BNSLs with certain structures can exhibit the combined and collective properties of their building blocks and are widespread in the fields of electronics and magnetic devices.As most studies have focused on combined two-component NCs of different sizes for self-assembling BNSLs,there are a few studies on singlecomponent NCs of different sizes for the construction of BNSLs;this is especially true for Au NCs.Noble metallic Au NCs are an excellent candidate material because of their exceptional chemical stability,catalytic activity,process ability,and metallic nature;these characteristics provide them unique size-dependent optical and electronic properties as well as a wide variety of applications in sensing,imaging,electronic devices,medical diagnostics,and cancer therapeutics owing to their strong interactions with external electromagnetic fields.Therefore,it is important to develop a simple and efficient procedure to build BNSLs with different sizes ofAu NCs.In our study,we synthesized monodispersed (size distribution ＜ 10％) 6.0,7.3,and 9.6 nm Au NCs using dodecanethiol-stabilized 3.7 nm Au NCs as seeds through a seed-growth method in oleylamine.The obtained Au NCs exhibited morphology and nanocrystallinity (single-domain and polycrystalline) similar to those of Au seeds.As the size ofAu NCs increased from 3.7 to 6.0,7.3,and 9.6 nm,the surface plasmon resonance peaks narrowed and indicated a red shift.The oleylamine-functionalized 6.0,7.3,and 9.6 nm Au NCs were mixed with 3.7 nm Au NCs at certain concentration ratios.Au BNSLs with AB2 (hexagonal AlB2 structure),AB13 (NaZn13 structure),and AB (cubic NaCl structure) type were obtained through the solvent evaporation method.The (001) plane of the AlB2-type structure,(001) plane of the NaZn13-type structure,and (100) plane of NaCl-type structure superlattices were observed through transmission electron microscopy (TEM).The effective particle size ratios (y =Dsmall/Dlarge) serve as the critical determining factor in the formation of the BNSLs.The effective particle size of NCs is equal to the sum of the metal core diameter and twice the thicknesses of the surface ligand.In our study,the effective particle size Dsmall (Au seed) is 5.7 nm;the effective particle sizes Dlarge (6.0,7.3,and 9.6 nm Au NCs) are 9.0,10.3,and 12.6 nm,respectively.The effective particle size ratios y were therefore calculated to be 0.63,0.55,and 0.45,respectively.The relevant space filling principle predicted the stability of the AlB2,NaZn13,and NaCl-type structures in the range of 0.482 ＜ y ＜ 0.624,0.54 ＜ y ＜ 0.625,and y ＜ 0.458,respectively;the experimental results adequately matched the relevant space filling principle.The investigation of such a single nanocomponent as a building block is noteworthy with regard to the structures and properties of BNSLs as well as the potential development of novel meta-materials.关键词
种子生长法/金纳米晶/自组装/二元纳米晶超品格/结构Key words
Seed growth method/Au nanocrystal/Self-assembly/Binary nanocrystal superlattice/Structure分类
化学化工引用本文复制引用
赵亚楠,何敏,刘晓芳,刘斌,杨建辉..金二元纳米晶超晶格的自组装和结构表征[J].物理化学学报,2020,36(9):147-152,6.基金项目
The project was supported by the National Natural Science Foundation of China (21501141),the Cyrus Tang Foundation for Tang Scholar and the "Top-rated Discipline" construction scheme of Shaanxi higher education.国家自然科学基金(21501141),唐仲英基金会和陕西省高等教育“一流学科”建设计划资助项目 （21501141）
