Preparation Of Novel Photocatalytic Nanomaterials And Their Oxidation Of NO And Hydrogen Production

At present,environmental pollution is serious and energy crisis is intensified.Photocatalysis has the unique properties of depth reaction at room temperature and direct use of solar energy as a light source to drive the reaction,becoming an ideal technology which can control environmental pollution and clean energy production.Photocatalytic applications is very promising in the elimination of low concentrations of NO_x?an air pollutants?,and has provided a broad space for solve the energy crisis.In this dissertation,the synthesis of novel materials and their application in solving practical problems are explored.Some problems such as low separation efficiency of photo-generated electrons and holes,low visible light activity and poor stability of the catalyst are solved.The main research contents are as follows:1.Microwave synthesis of CNT-threaded CeO₂ with mesoporous structure for photocatalytic NO oxidationThe selective heating of carbon nanotubes via microwave method was used to induce the adsorption and nucleation of Ce³⁺on the surface of CNTs.The CNT-threaded CeO₂ with mesoporous composite was prepared and used in the photocatalytic NO oxidation reaction of flow phase.In this composite,CeO₂ mesoporous crystals provide effective light capture and adsorption properties of reactant;CeO₂-CNT interface constructed in situ reaction via microwave is conducive to rapid electron transfer;discontinuous distribution of CeO₂ making it possible for CNT to crosslink forming a3D conductive network which further promoted carriers'separation as well as inhibited recombination,resulting in a 62%of removal rate of NO under 365 nm UV light irradiation.2.Uncoordinated amine groups of NH₂-UiO-66?Zr?to anchor Cu?II?as visible-light-driven photocatalysts for NO oxidationCombined with the respective advantages of MOFs and bivalent copper,Cu???-NH₂-UiO-66?Zr?was synthesized by the coordination of Cu^?with the amino group?-NH₂?on the NH₂-UiO-66 skeleton.The unique interaction between Cu^?and NH₂-UiO-66?Zr?greatly improves the removal rate of NO up to 90%under visible light irradiation,and results in an excellent stability.This result solves the problems of low performance under visible light irradiation and poor stability in the field of NO oxidation.3.Uncoordinated amine groups of NH₂-MIL-125?Ti?to anchor Cu???as Catalysts for Efficient Visible-Light-Driven H₂ productionCu???-NH₂-MIL-125?Ti?composite was prepared via a similar coordination-assisted strategy.This synthesis is based on the utilization of coordination between Cu^?and the free amine groups?-NH₂?at the skeleton of NH₂-MIL-125?Ti?.Introduction of the Cu species leads to a 9.5 times higher activity,compared to activity of Pt/NH₂-MIL-125?Ti?.The enhanced photocatalytic activity can be ascribe to the fact that noble metal-free copper species form a new electron transfer path with organic linkers through coordination between Cu^?and-NH₂ at linker which involves a ligand to metal charge transfer?LMCT?,promoting the more efficient electron transfer directly.