Morphology Controlling,Polythiophe Modification And Gas Sensing Properties Of Nano-zinc Oxide

Volatile organic compounds are toxic and harmful substances that are harmful to the environment and human health.Therefore,it has important practical significance to effectively detect such substances.In recent years,the research of metal oxide semiconductors gas sensing materials has been popular,in which nano-zinc oxide has received extensive attention from researchers,because of its easy to obtain raw materials,low prices,environmentally friendly,and other advantages.In order to reduce the working temperature,improve the sensitivity of the test,modifying and regulating the morphology of zinc oxide can improve its gas sensitivity.Conductive polymer materials are widely used in electrochemistry and catalysis because of their excellent electrical conductivity.Polythiophene and its derivatives are one of the most important conductive polymers.Polythiophene-modified zinc oxide is less used for the detection of harmful gases.Therefore,it is expected to improve the gas-sensing properties by polythiophene-modified nano-zinc oxide and realize the application in the detection of harmful volatile organic compounds.Based on the above,nano-zinc oxides with different morphology were synthesized by controlling the experimental parameters,and modified it.The gas sensing properties of zinc oxide were systematically studied by exploring the influence of morphology and doping amount.The main contents and conclusions are as follows:(1)Nano-zinc oxide was synthesized by hydrothermal method using zinc nitrate and tetraethylammonium hydroxide under the condition of no surfactant.The structure,morphology and gas sensing properties were studied.The results show that the response value of the rod-shaped nano-zinc oxide to 100 ppm propylene glycol and ethanolamine gas is 49.5 and 69.9 at an operating temperature of 300?,indicating that it can effectively detected propylene glycol and ethanolamine at low concentrations.(2)The zinc oxide particles were prepared by hydrothermal method using zinc acetate,sodium hydroxide to regulate pH,and the reaction parameters were controlled.The gas sensing properties were also studied.The results showed that the optimal operating temperature of zinc oxide was 140? and the response to propylene glycol was higher,and the response value to 100 ppm propylene glycol was 16.7.Response time is 1s,with good reversibility,but low selectivity.(3)The morphology and gas-sensing properties of ZnO particles /polythiophene composites with different polythiophene content were synthesized by adjusting the experimental parameters.The results show that the polythiophene can enhance the gas-sensing properties of zinc oxide.When theamount of polythiophene is 10 wt.%,the composites show good selectivity and response to propylene glycol.(4)The zeolite zinc oxide was prepared by hydrothermal synthesis using zinc nitrate and sodium hydroxide as raw materials,and its gas sensing performance was studied.The results showed that the optimal working temperature of flaky zinc oxide was 200 ?,the response value to ethanolamine was higher,the response value was 27.9 at the concentration of 100 ppm and the response time was 1s.(5)The composite materials of different polythiophene modified flaky zinc oxide were prepared by hydrothermal method,The gas sensing performance results show that the modified zinc oxide has better gas sensitivity than that of pure flake zinc oxide.When the compound amount is 8wt.%,it has the highest response value to ethanolamine gas.The response value at the same operating temperature is increased by 6 times,and has excellent selectivity,response speed and reversibility.