Preparation And H₂S Gas Sensing Investigation Of SnO₂ Quantum Wire/holey Graphene Oxide Nanocomposites

The changes in the content of hydrogen sulphide gas in human body can indicate whether there is latent disease in the body.However,the sensor is required to have high sensitivity and low detection limit at room temperature.The material of the quantum structure of SnO₂ can produce quantum confinement effect and effectively improve the gas sensitivity.With graphene,it can effectively improve the gas sensitivity of the material and reduce the operating temperature to a certain extent.Functionalized graphene can be used to introduce groups or defects on the basis of original graphene materials to further improve the gas sensitivity of the material.Therefore,this paper using one-step synthesis of SnO₂ quantum wire and holey structure of graphene,at room temperature can to test the hydrogen sulfide,the test results have high sensitivity,low detection limit and good selectivity.According to the experimental results,the performance improvement mechanism is discussed.The detailed work is as follows:First,the use of microwave method in oleic acid oil amine in the oil phase system,the use of long chain organic molecules space restriction,regulation to join the amount of oil amine and reaction time,get the best of the reaction conditions of synthesis of SnO₂ quantum wires.In this paper,the quantum wire morphology,quantum effect and structure are characterized,and then the pure quantum wire is preliminarily tested for H₂ S sensitivity.The results show that the quantum boundary of SnO₂ quantum has the quantum limit effect.At room temperature,the sensitivity of 1ppm H₂ S is 2.26,and the stability of dynamic cycling test is good.Second,to improve the Hummers of graphene as raw materials,prepared by the etching with potassium permanganate strong oxidizer,regulating the etching agent,reaction time and reaction temperature are the best reaction conditions of preparation of holey graphene,using a variety of characterization methods observation holey morphology and structure.The results show that the prepared holey graphene has a single layer and the higher quality is beneficial to the preparation of the subsequent complex.Third,using one-step in microwave reactor system combined with the oil phase in the synthesis of holey SnO₂ quantum wire and graphene composite materials,the composite material has carried on the morphology structure characterization,and applies the system of modernism and gas sensitive performance tests.The compound of holey graphene was selected as the control group to explore the influence of holey graphene content on the gas sensitivity of composite materials.The results showed that the sensitivity of SnO₂ quantum wire/holey graphene composites at 1ppm was up to 42.6 in 1ppm and the limit of 300 ppb was detected.Compared with the experimental results,the properties of composites prepared by this paper are ten times better than those of the similar system in the literature.The mechanism of the high performance of the gas sensitive properties of SnO₂ quantum wire/holey graphene composite materials was discussed.