Preparation And Performance Of RGO/AB₂S₄ Gas Sensitive Composite

With the rapid development of science and technology in modern society,people's requirements for living environment and quality are generally increasing.In common workplaces,such as factory workshops,laboratories,etc,some colorless and odorless traces of harmful gases are difficult to detect,but they will cause serious harm to the safe production of places and people's healthy life.Therefore,the detection of such trace gases is extremely urgent.Ethanol gas has low toxicity,long time contacting will make people face fever,limbs cold,headache and so on.In order to detect ethanol gas more effectively and quickly,spinel sulfide is combined with graphene in this paper to detect ethanol gas.Designing and synthesizing a variety of composite materials of AB₂S₄ spinel sulfide and rGO nanosheets as ethanol gas sensing materials,and explore its gas sensitivity to ethanol gas and its gas sensitivity mechanism.CuCo₂S₄ and rGO/CuCo₂S₄ were synthesized by a simple hydrothermal method.The morphological and structural characteristics of materials are studied by XRD,SEM,TEM,XPS and other characterization techniques.A comparative experiment was designed to compare the gas-sensing performance of CuCo₂S₄ and rGO/CuCo₂S₄ gas-sensing materials to ethanol.The results show that when the amount of graphene added is 0.6 wt%,the gas-sensing performance of the device is the best,the operating temperature is reduced from 220?to 180?,the response is increased from 2.5 to 5.8,and the recovery time is shortened by 7.5 s.ZnIn₂S₄ and rGO/ZnIn₂S₄ were prepared by the alcohol heating method.The gas sensitivity of rGO/ZnIn₂S₄ composites containing different ratios of rGO to ethanol was discussed.The results show that the 0.3 wt%-rGO/ZnIn₂S₄ gas sensor has a response value of8.1 to 100 ppm ethanol at the optimum operating temperature of 160?,which is 40?lower than the optimum operating temperature of the ZnIn₂S₄ sensor,and the sensitivity is 2.8 higher.Due to the large specific surface area of rGO and the formation of p-p heterojunction between ZnIn₂S₄ and rGO,the rGO/ZnIn₂S₄ sensor has excellent gas sensitivity.NiCo₂S₄ and rGO/NiCo₂S₄ were prepared by one-step solvothermal method.The gas sensitivity of rGO/NiCo₂S₄ composites containing different ratios of rGO to ethanol was discussed.The gas sensitivity test results show that the optimal working temperature of the 0.7wt%-rGO/NiCo₂S₄ gas-sensitive composite material for 100 ppm ethanol is 60?lower than the single NiCo₂S₄ gas-sensitive material.And it has excellent selectivity,long-term stability and repeatability for ethanol gas.