Research On Design Method Of Hydrogen Sensor Based On Molybdenum Sulfide

As a clean and renewable energy source,hydrogen is widely used in industry and daily life.At present,many countries are vigorously promoting the development of hydrogen energy.However,hydrogen is colorless,odorless,flammable,and explosive.Therefore,as the application range of hydrogen energy expands,effective monitoring methods are required to ensure safety.Hydrogen sensors are widely researched and applied because They can be directly distributed and networked in the measured environment,and they can achieve full coverage and all-weather real-time hydrogen monitoring.However,metal oxide hydrogen sensors,whose hydrogen-sensitive materials work in high-temperature environments,have potential safety hazards.Therefore,this article aims to design a resistance type hydro gen sensor using Mo S2 as a hydrogen-sensitive material.The excellent gas-sensing characteristics and low cost of Mo S2 make the designed hydrogen sensor working at normal temperature.The design and research of the sensor is divided into three parts: gas-sensitive material,gas-sensitive structure,and interface detection circuit.First,the theoretical basis of Mo S2 as a gas-sensitive material is studied.The hydrogen sensing mechanism of Mo S2 materials is modeled and analyzed at the micro level.Based on the calculation of density functional theory,the adsorption of H2 molecules on the surface of single-layer 1T and 2H Mo S2 surfaces is analyzed in detail.Combining the density of states and charge transfer,the interaction between adjacent atoms between the H2 molecule and the monolayer Mo S2 is explained,and the reason why the adsorption energy shows a large difference is explained.It is proved that Mo S2 material can be used for hydrogen sensing from the theoretical level,which provides a strong theoretical support for the design of hydrogen sensors.Moreover,based on theoretical analysis,2H phase Mo S2 with moderate adsorption energy was selected as the hydrogen-sensitive material.Next,a gas-sensitive structure was designed to convert various physical and chemical changes caused by the adsorption and desorption of hydrogen on the 2H phase Mo S2 into electrical signals.In order to determine the type of gas-sensitive structure used in the hydrogen sensor,the sintered and thick-film gas-sensitive structures is established and simulated used COMSOL software.Through the simulation results,the electrical characteristics of the two structures are analyzed in detail under the initial conditions.After comparison,the thick-film gas-sensitive structure with an initial resistance less than 100 k? is used.Finally,the preparation,assembly,debugging and use methods of Mo S2 hydrogen sensor working at room temperature are given.The interface detection circuit is designed for the gas-sensitive structure,and the simulation,production and testing are carried out.The detection circuit contains three parts: electric bridge,amplification and conversion.It is powered by ±12 V power supply.In the balanced state of the bridge,the power consumption is 78.85 m W.