Preparation And Characterization Of Porous Nanometer Zinc Oxide

Nowadays, various gases are being used and some of these are very dangerous,especially acetone, a colorless, odorless gas that is explosive at low concentration. Soit's necessary to use gas sensor to detect leakages and ZnO is a good material to makegas sensor, moreover, because of the large specific surface area, porous ZnO is the studykey point.In the experiments report here, the author used zinc nitrate as raw material,hexamethylenetetramine as template agent to prepare the rod-like, flower-like,cabbage-like hollow ZnO nano-tubes successfully via a simple hydrothermal synthesismethod. Use SEM/XRD has been made to characterize samples.The author used hydrothermal method to heat the mixture (ammonia water and zincnitrate) at 120°C for 4 hours to the obtain rod-like ZnO, which is standard regularhexagon wurtzute and the length is 500nm, the preferred growth face is along the (100)planes.An additional process was by coating different mixtures on indium titanium (ITO)glass substrates. When these were coated with C₁₆H₃₆O₄Ti, followed by hydrothermaltreatment the mixture (zinc nitrate and hexamethylenetetramine) at 100°C for 4 hours.The product was hollow nanometer ZnO tubes, with a diameter in the order of 200nmand length about 500nm. When the ITO glass substrate was coated with a mixture ofC₁₆H₃₆O₄Ti, C₂H₅OH, HNO₃ and heated it at 450°C for 0.5 hour. the resulting ZnOcrystals were flower-like hollow ZnO nano-tubes. When coated the mixture C₁₆H₃₆O₄Tiand H₂O and heated at 450°C for 0.5 hour, a cabbage-like lamellar structure ZnO result,this is the first time that such novel type ZnO has been obtained by such a simplemethod. Further examination showed that within the cabbage-like ZnO has TiO₂ ball inthe order of 2μm and outside is lamellar structure ZnOTherefore, the author synthesis the rod-like, flower-like, cabbage-like hollow ZnOnano-tubes successfully. Some of specific structures ZnO have large specific surfacearea. Especially the cabbage-like lamellar structure ZnO, which is the first to be synthesised in the world, and it should have important applications as gas sensor.