Solution Synthesis Of Indium-based Ⅲ-Ⅵ Group Semiconductor Hierachical Nanostructures And Their Properties

The objective of this dissertation is to explore new avenue for solution-based chemical routes to prepare indium-basedâ…¢-â…¥group inorganic semiconductor nanomaterials.Based on a wide and in-depth literature investigation,the hydrothermal and solvothermal system were selected as the research field.Organic molecule, biological molecule and polymer additive served as structure-directing agents,a series of functional nanostructured materials including InOOH,In(OH)₃,In₂O₃ and In₂S₃ have been obtained.The morphology,crystal structure,effective condition and formation mechanism of the products have been studied.In addition,the different morphologies on their properties have also been investigated.The main points are summarized as follows:1.A ultrasonic-assisted solution route to fabricate InOOH 3D structures assembled with nanowires has been proposed.Organic amine molecules which can serve as structure-directing agent in this experiment facilitate the formation of rod-like structures.On the basis of some parallel experiments,the energy from the sonication process induced the formation of uniform seeds,which favored the formation of nanowires with uniform diameters under solvothermal condition.The synthesis technique involving several methods can be extended to the preparation of other inorganic functional materials with desired structures.2.β-In₂S₃ uniform flower-like nanostructures with the average diameter of 400 nm can be obtained via an L-cysteine-assisted hydrothermal process.The growth mechanism reveals that the combination of In³⁺ ions and L-cysteine in the reaction solution produced the complex,which served as both the indium source and the sulfur source.The porousβ-In₂S₃ with a ultra-high surface area can contribute to the potential application in building photocatalysis devices.This environmentally benign technique can widely be used to fabricate other metal sulfide nanomaterials.3.A two-step technique has been applied in the synthesis of C-In₂O₃ nanostructures. Firstly,nanostructured In(OH)₃ with different morphologies assembled by small nanocubes has been prepared via a hydrothermal process,where the intermediates show the organic molecules and the biological molecules have the influence on the growth and oriented aggregation of these building block.And then nanostructured C-In₂O₃,inheriting its precursor In(OH)₃ morphologies,has been synthesized via heat treatment.The C-In₂O₃ with special structures shows great potential in catalysis,sensor and photoelectronics.4.InOOH with different morphologies,including 1D nanostructures and urchin-like hierarchical structures assembled by nanorods,can be constructed via a solvothermal method.Organic amine and polymer additive as capping agents selectively adsorb on the crystallographic facets of the growing crystals to achieve anisotropic crystal growth kinetically.H-In₂O₃ nanocrystals have been synthesized via heat treatment InOOH,and have inherited their precursors' morphologies. As-synthesized H-In₂O₃ exhibits excellent photocatalytic activity in the photodegradation of RhB solution under UV light irradiation,which is attributed to the special structures,size effects of nanorods and large surface area.