Study On Polypeptide Based Metal Oxide Semiconductor Materials And CO Gas Sensitive Properties

While the rapid development of science and technology continues to improve the convenience of people's lives,the toxic gases emitted by industrial production have also caused certain pollution to the natural environment.Some toxic gases(such as carbon monoxide)are colorless and odorless gases,which are difficult to detect in time and are more likely to pose a threat to people's health.Therefore,how to detect toxic gases accurately and efficiently,and prevent them before they happen,has become an issue of widespread concern to researchers all over the world.The gas-sensing performance of materials with SnO₂ as the main body is developed.Starting from the structure and morphology of the material,the gas-sensing performance is tested and explored.The main content and innovation are shown in the following aspects:(1)The phenylalanine dipeptide was dissolved in dimethyl sulfoxide(DMSO)by the solvent method and then inserted into deionized water for self-assembly,and finally nanotubes were obtained.At the same time,a simple hydrothermal method was used to prepare granular SnO₂.The response of the SnO₂ gas sensor to 40 ppm carbon monoxide under the environment of ultraviolet light is 3.2;on this basis,a connection is added as a load to recombine with SnO₂.The response value of the 0.5 wt%nano/SnO₂ composite gas sensor to 40 ppm carbon monoxide is increased from 3.2 to 4.7,and its performance is improved by 47%;at the same time,it has excellent performance in repeatability and stability.(2)By adding MoS₂,SnO₂ particles can be uniformly attached to the surface.After testing,it was found that the response value of the 0.5 wt%MoS₂/SnO₂ composite gas sensor to 40 ppm carbon monoxide was 4.9.Compared with SnO₂,its performance was improved by 53%.The response and recovery time were 43 s and 36 s,respectively;further use of peptides to adjust the MoS₂/SnO₂ composite material,so that SnO₂ changed from granular to flake.The gas sensitivity test shows that the MoS₂/SnO₂ composite gas sensor adjusted by 0.5 wt%peptide has increased its response value to 40 ppm carbon monoxide from 4.9 to 6.4,and the response value has increased by 30%;and the response and recovery time at 40 ppm carbon monoxide They are 50 s and 22 s respectively;they also have excellent performance in repeatability and stability.(3)The specific surface area of SnO₂ exposed to gas is increased by simply mixing graphene as a load with SnO₂.The response value of the 0.5 wt%graphene/SnO₂composite gas sensor to 40 ppm carbon monoxide reached 5.9,of which 0.5 wt%was the best ratio;the response and recovery time were 37 s and 58 s,respectively;good repeatability and stability Excellent;on this basis,the use of peptides to regulate the composite material makes SnO₂ change from granular to flake.The gas sensitivity test showed that the addition of peptides formed a new composite structure.The addition of0.5 wt%peptides increased the response value of graphene/SnO₂ to 40 ppm carbon monoxide from 5.9 to 7.2,and the response value increased by 22%;response and recovery time Respectively 29 s and 22 s;good repeatability and excellent stability.