Research On Fabrication Of Tin Diselenide Based Gas Sensors For Atmospheric Environmental Gaseous Pollutants And Their Sensing Properties

With the rapid economic development and the advancement of urbanization,the emissions of polluting gases from industry and life have become more and more serious,and the problem of atmospheric pollution needs to be solved urgently.Atmospheric gaseous pollutants are the main component of atmospheric environmental pollution.Gaseous pollutants continue to increase and accumulate in the environment,causing great damage to the ecosystem and living environment,seriously affecting people’s normal life,and causing extreme damage to the country and individuals.Therefore,the development of high-performance,portable and low-cost gas sensors to effectively monitor the composition and concentration of toxic gases in the atmosphere is of great significance to public safety and health.This paper is dedicated to the construction of gas sensors with high sensitivity,low detection limit,small portability,low power consumption,high selectivity,and low cost for gaseous pollutants in the atmospheric environment.The micro-nano films based on heterostructure of nano-modified tin diselenide（Sn Se₂）were studied,and the ammonia（NH₃）sensor based on Au-Sn Se₂Schottky,nitrogen dioxide（NO₂）sensor based on MOFs-derived Sn O₂/Sn Se₂heterojunction,carbon monoxide（CO）sensor based on MOFs-derived Zn O/Sn Se₂heterojunction,and sulfur dioxide（SO₂）sensor based on g-C₃N₄/Sn Se₂heterojunction were constructed.The heterostructure materials that are highly sensitive to the target gases were prepared by solvothermal method and MOFs template method.And the high-performance,high-stability sensors were successfully constructed on the epoxy resin substrate with interdigital electrodes and the substrate of the indirectly heated sensor by means of screen printing and drip coating.The gas sensitivity performance of the developed sensors to the common gases（NH₃,NO₂,CO and SO₂）,which are gaseous pollutants in the atmospheric environment,has been systematically studied.A series of characterization methods such as XRD,XPS,SEM and TEM were used to investigate the microstructure and element composition of the sensitive film.The sensitive mechanism was deeply explored combining the characterization results,first-principles simulations,heterostructures,noble metal catalysis and surface oxygen vacancy concentration theory.The research results show that the sensors developed in this paper have excellent selectivity,ultra-high sensitivity,good repeatability and long-term stability for the target gases,achieve high-precision detection of gaseous pollutants in the atmospheric environment,and have far-reaching significance for environmental monitoring.In this paper,high-performance gas sensors are constructed for the four atmospheric pollutants,NH₃,NO₂,CO and SO₂,and their sensing characteristics and mechanisms are deeply explored.It opens up a new application field for thin film gas sensors based on the heterostructure of tin diselenide,and also provides powerful theoretical guidance for the realization of high-performance,low-cost atmospheric environment gaseous pollutants detection.As the same time,this work has important reference value for the accurate and rapid detection of toxic substances in the atmospheric environment and the development of gas detection devices.