Preparation Of Nanobelts Using Composite-Hydroxide-Mediated Method

Nanomaterials have at least one-dimensional size in the range of nanometer scale. Nanobelts are quasi-one-dimensional materials with rectangular cross-section and nanometer scale thickness,the width of which is up to several hundred nanometers, the ratio between width and thickness is great.Nanobelts have aroused worldwide interest because of their unique electrical,optical and mechanical properties.A number of methods have been used to synthesize nanobelts,such as physical vapor deposition,chemical vapor deposition,low-temperature liquid,hydrothermal, microemulsion,templates method,and so on.In this paper,several different kinds of nanobelts were synthesized through a composite-hydroxide-mediated(CHM)method. The morphology,composition,and some physical properties of the products were studied.Firstly,KCu₃S₂ nanobelts are obtained by using the CHM method.XRD results and electron diffraction(ED)patterns indicate that the nanowires are single crystals with monoclinal structure.Transmission electron microscope(TEM)and field emiddion scanning electron microscope(FESEM)results reveal that the width of KCu₃S₂ nanobelts are typically 0.5～5μm,thickness of one layer of the belt is about 30～50nm,and the length reaches several hundred micrometers.The fluorescence properties of the nanobelts were characterized and discussed.The electric properties of KCu₃S₂ nanobelts were also studied by mease of measurement of resistivity of individual nanobelts through a micro-operation method.The result ofâ… -â…¤characteristics of the nenobelts indicates that KCu₃S₂ are semiconductor materials; KCu₃S₂ nanobelts are sensitive to ultraviolet.This optical sensitivity of the nanobelt may be useful for biological labeling.Secondly,the CuS nanostructure were also synthesized by using the CHM method. XRD and ED analysis indicate that the nanowires are hexagonal CuS single crystal. TEM and SEM results reveal that the morphology of the CuS is honeycomb-like architecture,which is self-sembled by CuS nanoflakes with a thickness of about 50nm. The reaction mechanism is also discussed and a growth mechanism is proposed.The CuS nanostructures reported here may have potential applications in the optoelectronic devices. Thirdly,we prepared ultralong La(OH)₃,Er:La(OH)₃ and Ce:La(OH)₃,nanobelts by using CHM method.XRD results indicate that the products are hexagonal phase. The detectable conductive behavior of a single nanobelts promises the potential application of the La(OH)₃ nanobelts in sensors,by designing the corresponding electronic devices.SEM results reveal that the length of these nanowires are several hundreds micrometers.The effect of rare earth dopants on fluorescence properties of La(OH)₃ was discussed.In summary,a systematic investigation has been conducted on the preparation, characterization,and growth mechanism of KCu₃S₂,CuS,La(OH)₃,Er:La(OH)₃ and Ce:La(OH)₃ nanostructures.Some important and novel experimental results have been obtained.