Preparations And Performanceof ZnO Nanotrees And ZnO Composite Materials

Morphology of nanomaterials has an important influence on its performance.The nanomaterials have many excellent properties because of special morphology and unique structure,and have become hot spots of research in the field of material science.ZnO is a N type semiconductor metal oxide with direct band gap,and it has many excellent properties such as wide band gap,high electron mobility,and so on,and it's applied in the photocatalysis,electrochemical,gas sensor,etc.The ZnO nanotrees array was synthesized by water bath method in this subject and we studied their performance in the aspects of photocatalysis and electrochemical.The main contents and results were as follows:(1)The nanotrees array of ZnO(marked as ZnO-NTs)was successfully prepared on the substrates of conductive glasses(marked as ITO)by two stage growth method using Zinc nitrate as the source of zinc,and the influence of different preparation conditions on the morphology of ZnO was discussed.The ZnO-NTs have intricate branching structures,which provide a specific surface area,electronic channels and active center,etc.Therefore,the ZnO-NTs have a high photocatalytic activity.The ZnO-NTs' efficiency of the degradation of RhB is 1.8 times that of ordinary ZnO powder under the irradiation of UV light and 2.4 times under the irradiation of visible light.Meanwhile,In terms of electrochemical properties,the ZnO-NTs modified electrode has a good performance in the detection of dopamine(DA).Compared with common bare electrode,the oxidation peak of dopamine(DA)on the ZnO-NTs modified electrode has a negative shif(182mV?76mV)and the peak current increases.After optimizing the experimental conditions,the sensor exhibits a wide linear response range of 1?100 M(correlation coefficient is 0.995,the signal to noise ratio is 3),and the detection limit is 3.3×10-7M.(2)Some nano Ag particles were deposited on the surface of ZnO-NTs using silver nitrate as the source of silver and sodium hydride as the reducing agent,then the ZnO composite material(Ag@ZnO-NTs)loaded with noble metal was prepared.Some uniform and fine Au particles were deposited on the surface of ZnO-NTs by ion sputtering method,and ZnO composite material(Au@ZnO-NTs)loaded with noble metal was prepared.The characterization of Ag@ZnO-NTs and Au@ZnO-NTs was characterized,and its application in photocatalytic degradation of pollutants was studied.Photocatalytic experiments showed that the ZnO composite loaded with noble metals showed a better photocatalytic activity than ZnO-NTs.(3)A solution with a certain concentration of ammonium fluoride and urea is configured and some TiO2 was deposited on the surface of ZnO-NTs after the conditions of heating and the ZnO-NTs composites(TiO2@ZnO-NTs)loaded with TiO2 were prepared.The characterization of TiO2@ZnO-NTs was carried out,and its application in photocatalytic degradation of pollutants was studied.Photocatalytic experiments showed that the ZnO composite loaded with Ti02 showed a excellent photocatalytic performance.