Theoretical Study On Adsorption Of BTAH And Gas Molecules On The Surface Of Nanomaterials

In recent years,due to its excellent physical and chemical properties,nanomaterials have made considerable progress in various research fields.Especially the large specific surface area and high surface activity of nanomaterials make the surface reaction of nanomaterials active and tend to adsorb small molecules on the surface.The research based on this surface adsorption property can be used in the fields of surface modification,catalysis,diffusion,sensing and so on.Surface adsorption is a common method for surface modification of nanoparticles.Nano-copper particles are regarded as potential advanced packaging materials due to their excellent thermoelectric properties and low prices,but they are difficult to be applied on a large scale owning to their easy oxidation characteristics.Therefore,the study of the adsorption between the surface of copper nanoparticles and small organic molecules is helpful to improve the oxidation resistance of copper nanoparticles and promote their large-scale application in the future.For surface adsorption of nanomaterials,in addition to surface modification and modification,the adsorption characteristics of nanomaterials can also be used for gas detection.The 2D Si Se material,the fourth group monochalcogenide compound,has good stability and low thermal conductivity.At present,the gas-sensing behavior of Si Se monolayer has not been fully and systematically studied,so it is very necessary to develop a gas-sensing sensor based on Si Se monolayer.In the thesis,some surface adsorption studies on low-dimensional metallic nanomaterials and non-metallic nanomaterials are carried out.From the perspective of mechanism exploration,the adsorption applications of nanomaterials for surface functionalization and gas detection are predicted,which provided solutions and theoretical basis for solving the problems encountered in the application of nanomaterials.The main contents of this study are as follows:（1）The Cu（100）,Cu（110）and Cu（111）plane of nano-copper surface are established,the different adsorption configurations of benzotriazole molecules（BTAH）are discussed,and the strength of the interaction between BTAH and the copper surface in different ways is explored.（2）Based on the interaction between BTAH and nano-copper surface,copper nanoparticles（Cu NPs）coated with BTAH were prepared.The morphology of the nanoparticles is observed by SEM and TEM.The oxidation resistance of the particles is analyzed by XRD and XPS.The thermal behavior and decomposition of the surface coating are analyzed by TG/DSC analysis.（3）The monolayer model of silicon selenide is established,and ten different gas molecules are adsorbed.The possibility of silicon selenide being used as sensitive material for gas sensor is explored based on the adsorption energy,charge transfer,and electrical properties.（4）The performance of the sensor is adjusted by stress to optimize the adsorption of NH₃ and SO₂.At the same time,the co-adsorption characteristics of NH₃ and SO₂are discussed.Finally,a single-layer silicon selenide device model is established,the sensing performance of silicon selenide is simulated,and the I-V curve change of adsorbed NH₃ is explored.