Synthesis And The Photoelectric Properties Of One-dimensional Nanomaterials

Environmental pollution has emerged as one of the greatest challenges to modern society in recent decades, which has threatened the human’s health and society development. Semiconductor photocatalyst has attracted wide attention because of its superior performance in degrading organic pollutants by using solar energy. Due to its fast electron transport rate and large specific surface area, one-dimensional (1D) nanomaterials opens wide and applicable applications, such as in the field of solar cells, photocatalyst, photoelectric devices and so on. In this thesis, vertically ordered and well crystallized ZnO nanowire arrays on indium tin oxide (ITO) or fluorine tin oxide (FTO) glass substrate were synthesized by a microwave-assisted hydrothermal method. These ZnO nanowire arrays show high photocatalystic activity even after several times recycle. At the same time, the ZnO@TiO2 core-shell nanowire arrays were obtained by sputtering TiO2 layer on the surface of the ZnO nanowire arrays with pulsed laser deposition technology. The photocatalytic properties of these 1D nanostructures were also studied. The main results are summarized as follows:(1) Vertically ordered and well crystallized long ZnO nanowire arrays were synthesized on ITO/FTO glass substrate by a miaowave-assisted hydrothermal method. Super-long ZnO nanowire arrays on ITO/FTO glass substrate have been obtained in a rather short time by using a self-made continuously dropping setup. ZnO nanowire arrays with different density can be obtained by adjusting the growth parameters, which provides a possibility to realize surface coating on these ZnO nanowires arrays.(2) The photocatalysis of the vertically ordered ZnO nanowire arrays were studied under ultraviolet irradiation. The samples have good photocatalytic activity and can be efficiently recovered and reused. It still maintains good photocatalytic performance even after seven times recycling. The SEM image of the ZnO nanowire samples after seven times cycles shows that the morphology and density of the nanowires have no obvious changes, which indicates that it still can be used for many more cycles. With good stability and recyclable performance, the sample has good potential for practical photocatalytic applications. This good photocatalytic performance of these 1D ZnO nanowire arrays are attributed to its fast electron transport rate and larger specific surface area.(3) The ZnO@TiO2 core-shell structure nanowire arrays were obtained by sputtering a TiO2 layer on the surface of the ZnO nanowire arrays with pulsed laser deposition technology. The thickness of the shell can be controlled by changing the number of sputtering pulses. This method is simple in operation and it provides a new way for the surface coating of 1D nanomaterials.