Preparation And Application Of Metal – Semiconductor Nanowires

With the development of nanotechnology, Nanometer materials become a new hotspot in the field of materials research. Metal-semiconducting composite materials which has considerable application prospect in energy conversion and micro devices with multiple functions. Metal-semiconducting composite materials play impotant roles in the filed of the new material. This paper mainly study on Preparation and properties of metal-semiconductor nanowires. The following is our significant work:Part one: A series of multilayer metal-semiconductor nanowires is synthesized with a method including two steps designed by us. The first step, multi-section Au-Fe, Ni-Ag-Ni, Ni-Cu-Ni and Ni-Ag-Cu-Ni nanowires are deposited in the AAO. The second step, these nanowires are transformed into-semiconductor nanowires through solution method. However, the multi-section structure of Au-Fe nanowires are mostly destroyed by NaOH when remove the AAO template. Therefore, we learn from bluing process in industry and change the multi-section Au-Fe nanowires into Au-iron oxide nanowires. In addition, Ni-Ag-Ni, Ni-Cu-Ni, Ni-Ag-Cu-Ni nanowires are changed into metal-sulfide structure by Na2 SX solution.Part two: Gold nanoparticals embedded maghemite hybrid nanowires are synthesized, which is novel and different from the method of traditional surface doping. We synthesized method is as follows: first, Au-Fe hybrid nanowires are deposited in AAO, then, the samples are delloied and heated in vacuum in the end. According to the experimental phenomena and results the reaction mechanism is proposed and validated. The results of XRD, SEM and TG technology proves that the structure of Au-Fe alloy nanowires change to γ-FeOOH first and then to γ-Fe2O3. The embedded gold particles are favorable to enhance reducing gas response properties of the hybrid nanowires, which is credited to the nano open-circuit Schottky junctions between γ-Fe2O3 and the Au nanoparticles. The gas sensing experiment data demonstrate that these hybrid nanowires are ideal sensing materials for ethanol, which have shown both high selectivity,high sensitivity and low detection limit.