Controllable Synthesis,Gas Sensing Properties And Electrochemical Properties Of SnO₂ Nanostructures

In this thesis,six kinds of SnO2 nanostructures with different morphologies have been successfully synthesized via a facile hydrothermal route without use of templates,substrates and surfactants.XRD,SEM,TEM,FT-IR,UV-vis,Raman and the BET method were used to examine the morphologies,phase structures and optical properties of the as-prepared SnO2.Meanwhile,the optimal synthesis parameter of porous nanostructures,sphere-like nanostructures and burr-sphere-like nanostructures of as-prepared materials have been explored,which realized the controllable morphology.In addition,the as-prepared samples were made into the gas sensor and the electrode material of the supercapacitor to test their gas sensing performance and electrochemical performance.The conclusions are as follows:1.Porous SnO2 nanorods array:the as-prepared materials had a good selectivity and sensitivity to acetone,ethanol,ethylene glycol and isopropanol at the optimum operating voltage of 4 V,4.5 V,3.5 V and 3.5 V respectively.The response of the sensor to methanol,ethanol and isopropanol under the concentration of 1000 ppm was 38.8,78.1 and 79.3.Meanwhile,the response to 400 ppm ethylene glycol was 37.7.The response-recovery time of the sensors to methanol,ethanol and isopropanol were short,but to ethylene glycol was a bit longer.Electrochemical parameters of porous Sno2 nanomaterials were obtained by cyclic voltammetry,chronopotentiometry and electrochemical impedance test,such as specific capacitance and impedance.2.Sphere-like SnO2 nanostructures:The material had a perfect selectivity and sensitivity to methanol,ethanol,ethylene glycol and isopropanol with the optimum operating voltage of 4.5 V,4.5 V,3.5 V and 3.5 V respectively.The response of the sensor to methanol,ethanol and isopropanol with the concentration of 1000 ppm was 31.5,64.0 and 79.3.Meanwhile,the response to 400 ppm ethylene glycol was 37.7.The response and recovery time of the sensor to methanol,ethanol and isopropanol was short,but to ethylene glycol was long.On electrochemical workstation,electrochemical parameters of spherical-like SnO2 nanomaterials were obtained by various electrochemical methods,such as specific capacitance and impedance.3.Cube-like SnO2 nanorods array:the material had good selectivity and sensitivity to acetone,ethanol,ether and isopropanol with the optimum operating voltage of 4.5 V,4.0 V,4.5 V and 3.5 V respectively.The response of the sensor to methanol,ethanol,ether and isopropanol with the concentration of 1000 ppm was 31.5,88.9,26.1 and 42.4.The response and recovery time of the sensor to ether compared with methanol,ethanol and isopropanol was a bit shorter.Electrochemical parameters of Cube-like SnO2 nanomaterials were obtained by various electrochemical methods,such as specific capacitance and impedance.4.Burr-sphere-like SnO2 nanostructures:the material had good selectivity and sensitivity to ethanol,ether,ethylene glycol and isopropanol with the optimum operating voltage of 3.5 V,3.0 V,5.0 V and 3.0 V respectively.The response of the sensor to ethylene glycol with the concentration of 1000 ppm was 69.5,93.0,36.5 and 58.6.The response and recovery time of the sensor to ethylene glycol compared with ethanol,ether and isopropanol was a bit longer.Electrochemical parameters of burr,sphere-like SnO2 nanomaterials were obtained by various electrochemical methods,such as specific capacitance and impedance.5.SnO2 nanorods array with six corners:on electrochemical workstation,electrochemical parameters of SnO2 nanomaterials with six corners were obtained by cyclic voltammetry,chronopotentiometry and electrochemical impedance test,such as specific capacitance and impedance.6.Flower-like SnO2 nanostructures:on electrochemical workstation,electrochemical parameters of flower-like SnO2 nanomaterials were obtained by cyclic voltammetry,chronopotentiometry and electrochemical impedance test,such as specific capacitance and impedance.