ZnO-based Gas Sensor For SF₆ Decomposition Products H₂S Detection Research

Sulfur hexafluoride(SF₆)is colorless and odorless,non-toxic and non-flammable gas,and it has good physical properties and chemical properties and high electrical.It is widely used and good isolated arc exterminating mediums,it is used in closed power systems and changeover switches.Because gas insulated switchgear(GIS)may produce some certain internal defects during manufacturing,installation and operation,the tools may be malfunction due to part discharge,meteor discharge,and local overheating during operation,resulting in SF₆ The gas decomposes in the air,and after some chemical reactions,it decomposes into SO₂ and SO₂F₂,SOF₂,SOF₄,CO₂ and CF₄,HF and H₂S and other steady gases.These decomposition gases can be used as a detection and evaluation method to detect the type of discharge failure and the degree of discharge.Among them,H₂S can be used to detect the discharge failure of the equipment and whether the discharge has the participation of insulating solid materials.Methods for discover H₂S include detect tube way,infrared absorb spectrum,gas phase and gas sensor method.As a special broad band semiconductor,ZnO has a lot of applications in solar battery,photocatalytic cancellation and gas sensors.This subject intends to use ZnO as a gas-sensitive material to make a gas sensor to detect the H₂S gas in the decomposition component of SF₆.This topic uses zinc acetate as the raw material and ethanol as the solvent.ZnO makings are prepared from solvothermal and most higher temperature calcination methods,and it are test by XRD,SEM and other test tools.Through the special results,the material synthesis terms are goal to intend ZnO materials.The synthesized ZnO is calcined and assembled into a gas sensor,and the H₂S gas is detected.By testing the best work temperature,selectivity,asking and recovery time,iterate and stability of ZnO,the show of ZnO is studied off different reaction conditions.Different gas sensitivity,and screen off the preparation terms with the best ask to H₂S gas.The feature results can be seen:the prepared thing is nano-particle ZnO.Preparater the prepared ZnO be a gas sensor.According to the goals of the gas sensitivity examination,the gas sensitivity of the makings is best when it temperature is 160?,and it time is 12 h.The running temperature at that time is 100?.In this working condition The sensitivity of ZnO thing to 100 ppm H₂S gas,is 45,the choosing is the best,and the asking and recovery time is 10 s-220 s.This topic uses nickel nitrate be the use of nickel and indium nitrate be the use of indium.A one-step dissolving method is used to make ZnO composite things.The effect of different compound scales in the structures and constructions of the synthesized materials is showed.XRD and SEM,mapping and XPS and other lots of testing,due to the characterization consequences,optimize the thing synthesis contexts,and make composite tools.The characterization results show that the method can prepare granular ZnO-NiO and ZnO-In₂O₃ materials.The gas sensitivity test outcomes see that if the complex ratio of Zn and Ni is 20:1,the gas choosing of the things are the best,and the best running temperature is 125?.At this temperature,the ZnO-NiO material has the best selectivity to 100 ppm H₂S gas.The highest choosing is 355,200 ppb is lowest limit,the asking time is 10 s,and the regain time after heating is 220 s.If the complex ratio of Zn and In is 15:1,the gas choosing of the thing is the best,and the best running temperature is 125?.At this temperature,the ZnO-In₂O₃ material has the best selectivity and the highest sensitivity to 100 ppm of H₂S gas.It is 190,the lowest detection concentration can be 500 ppb,and it asking-recovery time is 9 s-253 s.In summary,the materials synthesized in this goal have higher response,better choosing and most shorter response and recovery time for H₂S gas.It is really due of the goal of heterojunction that the choosing of the prepared things to H₂S gas has been clearly improved,and the modified material still has good repeatability and stability,and can be repeated for many times,which is beneficial to do.The found of H₂S gas during working can discover SF₆ equipment in time.The gas sensitive material making by this method has good application prospects and is worthy of further research.