Studies On Catalysts For CO₂ Photoreduction And Porous Materials For Dye Adsorption

The work in this thesis targeted two most important environmental issues:the green house effect caused by CO₂ emission and the organic pollutions in wastewater.We synthesized and characterized hydrogen titanate materials in order to convert CO₂ into CO through photocatalysis.Hydrogen titanate material has relatively high surface area and it is synthesized from TiO₂ precurser by hydrothermal method.Titanate nanotubes with phases and structural defects were obtained by varying the Na⁺/K⁺ ratio.These samples showed different photocatalytic performance,and some reached twice of that of P25’s under gas-solid flow condition with Xenon light.Our characterizations by XRD,TEM,Raman and other techniques showed that the structural homogeneity,the surface area and CO₂ adsorption capability could play important roles in the photocatalytic performance.We also discovered the photocatalytic reaction would change sample’s surface which could lead to efficiency loss.In other aspect,water pollution is a critical issue for the health of human population and sustainable development.We used a green method to prepare a nanosized MOF material,NH2-MIL-53（Al）in order to adsorb dye molecule.It’s found that amaranth and methyl blue molecules could be effectively adsorbed by NH2-MIL-53（Al）.The maximum adsorbed amount of methyl blue reaches 93 mg/g,and its kinetics fits pseudo-two order model.