Based On First-principle Reaction The Synthesis Agsno <sub> 2 </ Sub> Synthesis Mechanism And Computational Simulation

Synthesis mechanisms of the reactive synthesis of Ag/SnO₂ matrix composite were systematically studied by using density functional theory of the first principle.During the reactive synthesis of Ag/SnO₂ matrix composite,raw material is contain the 15wt%Sn of the metal alloy of AgsSn and the oxide of Ag₂O.According to the silver tin metal alloy phase diagram,there are two reactive routes in the course of reaction,namely oxidation reaction of the rich area of silver and the rich area of tin.In the reaction process of the rich area of silver,the Ag₅Sn transform the Ag(Sn)and separate with Ag₂O occurrence oxidation reaction.In the reaction process of the rich area of tin,the metal of Ag₅Sn transform into the metal alloy of Ag₃Sn first,and then the metal alloy of Ag₃Sn transform into the Sn(Ag),the structures one by one occurrence oxidation reaction with Ag₂O.So we designed four models,it is Ag₅Sn,Ag₃Sn,Ag(Sn),Sn(Ag),and designed the models with oxidation reaction,it is Ag₅Sn/O,Ag₆Sn₂O₄,Ag(Sn)/O,among them solid dissolved the body to build up the model of three kinds of different atoms percentage content.The total energy,bonds length and charge population,electronic structure of the crystal structures were comp -uted after full geometry optimization by using the CASTEP modules of the computation software Materials Studio.It is found that the total energy above-mentioned two reactive routes in the course of reaction is lower gradually,and the models after oxidation reaction is also lower gradually,the system inclines toward the stability,then two reaction routes all can take place.At the same time,it is found that the energy of crystal cell of Ag₂SnO₃ can be lower than the energy of crystal cell of Ag₅Sn/O,but it is higher than the energy of crystal cell of Ag(Sn)/O in the reaction outcome of the rich area of silver,so it is explained that the existence of Ag₂SnO₃ in the Ag/SnO₂ matrix composite.And it is found that the energy of crystal cell of Ag₆O₂/SnO₂ can be lower than the energy of crystal cell of Ag/SnO₂ in the reaction outcome of the rich area of tin,so it is explained that the existence of Ag₆O₂/SnO₂ in the SnO₂ gtain.And yet,it is found that the Sn-O bond length is shorter than Ag-O bond length,Electronics of the main occurrence of gain and loss is between the Sn,O,get the more stable tin oxide in the Ag/SnO2 matrix composite after computed the bonds length and charge population,electronic structure of the models,these results fit with the experiment relatively.During the reactive synthesis of Ag/SnO₂ matrix composite,we considered the structural variety of Ag₂O,according to the chemical reaction principle,the Ag₂O transform into the Ag₆O₂ first,and then the Ag₆O₂ resolves again for the single Ag,so we designed the models,it is Ag₂O and Ag₆O₂,at the same time,we also designed the models with oxidation reaction,it is Ag₂O/Sn and Ag₆O₂/Sn,according to the calculation of the total energy,we found than the total energy of Ag₆O₂ is smaller than the total energy of Ag₂O/Sn,this means that the model of Ag₆O₂ more stable than the model of Ag₂O/Sn,there is existence of surplus Ag₆O₂ in the Ag/SnO₂ matrix composite.