Atmosphere Treatment Of ZnO Nanorods And Piezoelectric Photocatalytic Performance Of ZnO NRs/titanium Mesh

Zinc oxide(ZnO)is a wide-gap semiconductor photocatalyst,which has the advantages of simple preparation,non-toxic,stable chemical properties,and piezoelectric properties.However,there are some problems such as low separation efficiency and low photocatalytic activity.Therefore,firstly,the ZnO nanorods were treated under atmosphere to create oxygen vacancy(Vo)defects in the crystal structure in this thesis,and the synergistic mechanism between the defects and the piezoelectric electric field was analyzed and discussed.secondly,ZnO nanorods array(ZnO NRs)was grown on the surface of the flexible titanium mesh.The ZnO nanorods were subjected to periodic bending deformation by shaker oscillator to simulate natural water flow,and piezoelectric electric field was generated to promote carrier separation.The specific work is as follows:ZnO nanorods were prepared with hydrazine hydrate as basic mineralizer and complexing agent.The effects of hydrazine hydrate dosage on morphology and degradation performance of ZnO nanorods were studied.Then,the prepared ZnO samples were treated under vacuum and hydrogen atmosphere respectively to investigate the effect of oxygen vacancy on the structure and properties of ZnO.The results show that when the molar ratio of hydrazine hydrate to Zinc acetate is 11,the ZnO nanorods have great morphology and excellent catalytic activity.The photocatalytic degradation efficiency of methyl orange(MO)solution by vacuum treated ZnO nanorods(V-ZnO)is 46.73%higher than that of untreated ZnO(A-ZnO).The piezoelectric degradation data show that the degradation efficiency of MO by V-ZnO is 40.74%higher than that by A-ZnO.After the oxygen defect was repaired in pure oxygen atmosphere,the piezoelectric catalytic performance decreased,indicating that Vo can improve the catalytic activity.ZnO NRs were grown on the surface of titanium mesh by hydrothermal method.By adjusting the impregnation times,temperature of heat treatment and hydrothermal time,ZnO NRs with regular morphology and excellent properties were prepared.The results show that the ZnO NRs with a diameter of about 300 nm and a length of about 3 μm when the impregnation times are 3 times,the heat treatment temperature is 350℃ and the hydrothermal growth time is 5 h.Under these conditions,the prepared ZnO has good morphology.Compared with ZnO NRs prepared on FTO and titanium substrate,ZnO NRs prepared on titanium net have good stability and wide applicability.The flow of water generated by a shaker was used to simulate the flow of water in the natural environment.The flexibility of the titanium mesh made it more deformed under the impact of water,and the collision of nanorods produced a larger piezoelectric electric field to separate the carriers.The results show that the piezoelectric photocatalytic efficiency of ZnO NRs/Titanium mesh is 228.93%and 162.97%higher than ZnO NRs/FTO and ZnO NRs/Titanium sheet,respectively.