Synthesis Of Complex Metal Oxide CdSnO₃ And Its Gas Sensitive Performance Of H₂S

Among semiconductor metal oxides,SnO₂ has been widely studied in gas-sensitive applications due to its large band gap,excellent electron mobility and excellent stability.Various methods have been used to synthesize it into useful nanostructural morphologies,such as nanosheets,nanoflowers,and quantum dots,to adjust its gas-sensitive properties.Despite a variety of structural choices,applications of SnO₂-based chemical sensors are limited by their lack of response to gases and accurate identification of interfering gas molecules.Composite metal oxides have better properties and excellent optical,electrical and magnetic properties than single metal oxides.This paper reports for the first time that the composite metal oxide CdSnO₃ as a new gas sensitive material can be used in the detection of hydrogen sulfide gas.Firstly,pure SnO₂ was synthesized by water bath method,and then cd-doped SnO₂,SnO₂-CdO composite material and CdSnO₃ composite metal oxide with different morphologies were prepared.The characterization and gas sensitivity tests show that the porous CdSnO₃ nanocube sensor has the best performance.This paper mainly includes the following contents:1.SnO₂ nanometer materials were obtained by water bath and calcining.The materials were characterized by X-ray electron diffraction?XRD?and scanning electron microscopy?SEM?.It is found that the sensor has the highest response to hydrogen sulfide gas when the operating temperature is 280°C,and the gas selectivity is better.In order to improve the response of the sensor,different quantities of cd-doped SnO₂ materials were prepared,and the gas-sensitive performance was tested.The response of the cd-doped SnO₂ gas sensor was 2 times higher than that of the pure SnO₂ gas sensor.2.The CdO was prepared by water bath method,and the CdO and the prepared SnO₂ were mixed and ground by molar ratio of 1:1 to produce CdO-SnO₂.The gas sensitivity test showed that the response was better than that of the Cd-doped SnO₂.The composite metal oxide CdSnO₃ nanoparticles were synthesized by coprecipitation.XRD and SEM were used to characterize the material.It was found that the material had a cubic shape before sintering and a granular shape after sintering.The sensitivity test results show that the gas sensor has a high sensitivity to hydrogen sulfide gas,but the response recovery problem appears.Therefore,it is expected to improve the performance of gas sensors by synthesizing porous CdSnO₃nanomaterials.3.PVP as templates,prepared by coprecipitation and waters the morphology of self-assembled porous cube CdSnO₃ nanocomposite was prepared by coprecipitation method first CdSnO₃ precursor,then CdSnO₃ precursor in a water bath pot 80?mixing after 6 hours,will receive the material by 700?high temperature calcined made porous cube 1 hour morphology CdSnO₃ nanocomposites,testing its gas sensitive properties,in 220?under the highest response of hydrogen sulfide,many of the gases?such as ethanol,acetone,carbon monoxide,hydrogen?showed excellent selectivity of hydrogen sulfide,analysis its reason may be the introduction of Cd element,and the electronegativity of Cd?1.69?is less than Sn?1.96?,lead to metal material surface oxygen key polarization is bigger,is advantageous to the adsorption of hydrogen sulfide in addition,due to the CdSnO₃ to the porous structure,specific surface area is big,is advantageous to the transmission and diffusion of gas,accelerate the sensor response and recovery,there are many O defects in structure,provides the rich active siteTherefore,the response of the sensor is improved,and a feasible scheme is proposed for the performance research of the sensor.