Synthesis And Characterization Of Metal-And Boron-Based One-Dimensional Micro/Nanomaterials

One-dimensional (1D) micro/nanostructures include micro/nanowires,micro/nanotubes, micro/nanobelts and coaxial micro/nanocables, whose lateraldimensions fall anywhere in the range of micro/nanometers. They have attractedcomprehensive attention due to their unique application in mesoscopic physics and thefabrication of nanodevices. Being the minimum units that can be used in effectiveelectron transportation and photons excitation, 1D nanostructures are considered as thekey of the assembly and functionalization of nanodevices. Consequently, how toprecisely control the anisotropic growth in nanoscale and further to realize theregulation of their sizes, dimensinalities, compositions, crystal structures and even theproperties may serve as a powerful tool for the research of the relationship between thestructures and properties of materials and may have signality in the exploitation offunctional materials and nanodevices. In this dissertation, valuable explorations havebeen carried out on the synthesis strategy of metal-based and boron-basedmicro/nanomaterials as well as their formation mechanisms and the functionalities ofas-prepared 1D micro/nanostructures.1D assemblies of Pt nanoparticles have been synthesized via a simplehydrothermal route using soluble starch as both template and reducing agent. Theformation mechanism of the product was studied in details. The electrochemicalbehaviors of dopamine (DA) and ascorbic acid (AA) on the preparedone-dimensionally assembled Pt nanoparticles modified glassy carbon electrode werestudied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV)techniques and showed satisfactory results for the simultaneous determination of DAand AA by resolving the overlapping voltammetric responses of DA and AA into twowell-defined voltammetric peaks. Ultralong copper submicron wires has been fabricated by a facile hydrothermal route under templateless and surfactantlessconditions. Vitamin C served as both the reductant and capping agent that can directthe growth of copper submicron wires. The crystallinity, purity, morphology, andstructure features of copper submicron wires were investigated and the growth mode ofthe copper submicron wires was proposed based on the tracking observation of thegrowth process.Metal-phosphates have mainly been of interest due to their specificbiocompatibility and proper bio-degradation, catalytic properties, and excellenttrans/vis magnetic properties. However, their use is limited by their brittleness anddifficulty in reshaping post-fabrication. One method of overcoming this disadvantageis to incorporate the phosphates within a composite material, combining themechanical strength of glass with the pliability of a plastics component. In our study,uniform metal-phosphates/C coaxial nanocables with iron-phosphates (FePOs)nanowires and cobalt-phosphates (CoPOs) as cores and carbonaceous matter as shellswere synthesized via a one-step hydrothermal method using ascorbic acid and/orsoluble starch as carbon source. Phase, composition and structure characterizationwere carried out on the products and the influence of the reactant content, reactiontemperature, and reaction time on the formation of the nanocables was investigated.The formation mechanism of the nanocables was studied by monitoring the reactionprocess in details.Boric acid has been recently discovered to be a new type of solid lubricant thatoffers extremely low friction efficient. By far, few reports on the synthesis andmicrotribological investigation of 1D boric acid nanostructures can be found in theliterature. Herein, an extremely facile synthesis route to ultralong boric acid submicronfibers was developed via the hydrolysis of borax. Phase, composition and structurecharacterization were carried out on the products. The formation mechanism of 1Dboric acid submicron structures was studied in details. Surface geometry of the boricacid submicron fibers was characterized by AFM in tapping mode and the lubricitywas investigated in comparison with the conventional solid lubricant mica by frictionimages and force-calibration curves using AFM/LFM in contact mode.