Preparation Of Mineral Based Composite Materials And Their Applications In Photocatalysis And Carbon Dioxide Adsorption

With the increase of population and the process of industrialization,environmental pollution.Energy crisis have gradually become thorny issues around the world.Natural clay minerals are characterized by rich adsorption and reaction activation sites,large reserves,low cost,environmental friendliness,etc,Therefore,it has received widespread attention in areas such as photocatalysis and gas adsorption.Among the common clay minerals,Kaolinite,Diatomite and Halloysite are three natural minerals with different morphologies.Kaolinite has a hexagonal flake morphology and abundant surface hydroxyl groups.Diatomite has cylindrical and disc-shaped morphology with high porosity.Halloysite has a tubular morphology and strong adsorption ability.Therefore,this paper takes Kaolinite,Diatomite and Halloysite as the basic research objects,and has synthesized three composite materials:Kaolinite/Titanium dioxide/Bi microspheres,Diatomite/Cuprous oxide and Halloysite/Porous carbon to study the photocatalytic degradation of methyl orange and CO₂ adsorption.（1）Kaolinite/Titanium dioxide/Bi microsphere composite（KTB）was synthesized based on kaolinite,and the performs of photocatalysis were further studied.The outcomes indicate that Ti O₂（T）in KTB samples was distributed on the kaolinite in the form of nanoparticles;The Bi microsphere（B）is composed of amorphous bismuth oxide Bi_xO_y shell and metal Bi core,which is loaded on nanometer titanium dioxide.Compared with T,B,kaolinite-Ti O₂ complex（KT）and Ti O₂-Bi ball complex（TB）,the photocatalytic rate of KTB complex sample increased significantly,and increased with the increase of KT addition;When the amount of KT added is 1.2g（1.2KTB）,the photocatalysis performance of the sample reaches the best.The photocatalysis performance per unit mass of Ti O₂ is 18.39,14.26 and 6.99 times of that of T,TB and KT,which greatly improves the photocatalysis performance of the material.（2）A series of Diatomite/Cuprous oxide（DC）composite photocatalysts with different cubic Cu₂O loading were synthesized using diatomite as carrier,and their performance of photocatalysis under visible light was further studied.The results showed that the surface of the cubic cuprous oxide particles prepared in the experiment was oxidized,and a thin layer of Cu O was formed on the surface and Cu₂O was formed inside.Compared with D and Cu₂O,the photocatalysis rate of DC samples improved evidently,and indicated a tendency of early raise and late fall with the improve of D proportion;When the mass of D added is 0.7 g（0.7DC）,the photocatalysis performance of the sample reaches the best,and the photocatalysis performance converted by unit mass Cu₂O reaches 7.5 times of that of pure Cu₂O.（3）Using polyvinylpyrrolidone（PVP）as carbon precursor,the porous Carbon/Halloysite composite（HC）was successfully prepared,and the CO₂ uptaken property of the material was studied.The outcomes indicate that the CO₂ uptaken property of the samples loaded with porous carbon（HC,AHC）was significantly improved compared with that of H and AH samples,At 0℃and 900 mm Hg,the CO₂adsorption capacity of HC samples is 2.11 and 2.00 times that of H and AH samples,respectively;The CO₂ adsorption capacity of AHC samples is 2.27 and 2.15 times that of H and AH samples,respectively.This thesis includes 45 figures,4 tables,and 151 references.