Functionalization of MoS2 and WS2 sulfide nanotubes: From controlled synthesis to organized assembly and function

目的本项目主要研究硫族化合物纳米管与有机配体和聚合物配体的功能化，以（i）调整硫族化合物纳米管在各种极性或非极性溶剂中的溶解度和/或将其整合到无机/聚合物杂化结构中，（ii）结合光激发或氧化还原配体（例如，用于光收集的金属卟啉）附着到管的侧壁，（in）附着纳米颗粒，例如金属（Au，Ag）、半导体（Au，Au）、半导体（Au，Ag）、半导体（Au，Ag，Au（iv）在氧化物或陶瓷表面上由MoSa纳米管制造薄膜，并由MoS 2和/或WS 2纳米管和聚电解质制备逐层组装的复合材料，（v）将配体附着到表面，以建立有组织的硫属化物纳米管组装体。拟议的研究将集中在MoS 2和WS 2纳米管，官能化策略基于通过过渡金属键合到硫属化物管的外表面层的三脚架或四脚架配体（Ni 2+或Co2+），其充当用于连接配体的胶。多配体携带用于连接其他功能分子或纳米颗粒的连接基团和用于调节纳米管与所连接的颗粒或分子之间的间隔的间隔基团。多脚配体可以作为侧基连接到嵌段共聚物的主链上，其中第二侧基携带官能配体，用作金属或半导体颗粒的锚基。聚合物配体方法的优点是纳米管/配体复合物不依赖于单键的稳定性，而是依赖于多官能对接。该方法的有效性已被证明与氮基三乙酸（NTA）的富勒烯型二硫化钼纳米粒子。 硫属元素纳米粒子的化学改性设计，这是特别感兴趣的润滑和冲击吸收（MoS 2，WSn）和电子性能（NbS 2，NbSe 2）。

ObjectivesThis project deals with the functionalization of chalcogenide nanotubes with organic and polymer ligands in order to(i) tailor the solubilities of chalcogenide nanotubes in various polar or unpolar solvents and/or to integrate them into inorganic/polymer hybrid structures,(ii) to bind photoexcitable or redoxactive ligands (e.g. metalloporphyrins for light harvesting) to the sidewalls of the tubes,(in) to attach nanoparticles such as metal (Au, Ag), semiconductor (ZnS, CdSe) particles to the sidewall of the tubes,(iv) to fabricate thin films from MoSa nanotubes on oxidic or ceramic surfaces and to produce layer-by-layer assembled composites from MoS2 and/or WS2 nanotubes and poiyelectrolytes,(v) attach ligands to the surface in order to build up organized assemblies of chalcogenide nanotubes.The proposed research will focus on MoS2 and WS2 nanotubes, which are available in sufficient amounts and quality.Methods and plan of operationThe functionalization strategy is based on tripod or tetrapod ligands which are bonded to the outer surface layer of the chalcogenide tube by transition metals (Ni2+ or Co2+) which act as a glue for the attachment of the ligand. The multiped ligand carries a linker group for the attachment of other functional molecules or nanoparticles and a spacer group for adjusting the separation between the nanotube and the particles or molecules attached. The multipod ligand can be attached as a sidegroup to the backbone of a block copolymer, where the second side group carries the functional ligands are acts as an anchor group for metal or semiconductor particles. The advantage of the polymer ligand approach is that the nanotube/ligand complex do not rely on the stability of a single bond but rather on multifunctional docking. The validity of this approach has been demonstrated with nitrilotriacetic acid (NTA) on fullerene-type MoSz nanoparticles.Significance of the proposed researchSuccessful performance of this research will provide a general methodology for a designed chemical modification of chalcogenide nanoparticles, which are of special interest for their lubricating and s hock-absorbing (MoS2, WSn) and electronic properties (NbS2, NbSe2).