Preparation And Performance Study Of Carbon Nitride Nano-materials And Composite Materials

With the speeding up of industrialization process of today's society,the world is facing serious environmental pollution and energy shortage problem today.Traditional semiconductor materials such as TiO2 has many shortcomings,in this paper,g-C3N4 is researched as a novel photocatalyst material.Graphitic C3N4(g-C3N4)has the superior performance,such as simple preparation method,low cost,high catalytic activity,as well as good visible light activity,no secondary pollution to the environment,therefore is a kind of environmentally photocatalyst.In recent years,g-C3N4 nanomaterial has attracted many researchers' attention.But electrons and holes for complex problems such as rapid limits the g-C3N4 in actual development.However,the photocatalytic efficiency of pure g-C3N4 is limited due to the fast recombination of its photo-generated electron-holes pairs.A large number of experimental results show that the study of the modification of g-C3N4 can restrain the composite risk of photon-generated carrier,and improve the quantum efficiency and light catalytic activity.This article studies the control of annealing temperature,annealing time,compositing with CeO2 and CeO2/g-C3N4/ZnO ternary nanocomposites impact on the surface morphology of the g-C3N4,chemical composition,crystal structure and catalytic performance.The main results were as follows:(1)The typical g-C3N4 photocatalyst is prepared by a traditional area thermal polymerization strategy.Through the different annealing temperature to control the surface morphology of g-C3N4,grain size and photocatalytic performance.When the annealing temperature is 550?,the absorption intensity and light catalytic activity of g-C3N4 samples reached the maximum under UV and visible light.(2)CeO2/g-C3N4 nanosheets are successfully synthesized via a simple and convenient solution combustion method.Controlling the aneealing temperature and the mass ratio of CeO2 changes the photocatalytic performance of CeO2/g-C3N4 nanosheets.In this study,it is found that when the CeO2 and g-C3N4 according to the quality ratio of 1:100 the photocatalytic performance reaches the maximum.The CeO2/g-C3N4 composite nanosheets are synthesized by chemical exfoliating of the bulk CeO2/g-C3N4 obtained(3)ZnO nanoparticles are successfully synthesized via a simple and convenient solution combustion method,through the different annealing temperature to control the surface morphology of ZnO,grain size and photocatalytic performance.When the annealing temperature is 600? and annealing time is 2 h,the hexagonal wurtzite ZnO is obtained.The ZnO sample annealed at 600? exhibits superior photocatalytic activity for the photodegradation of methyleneblue(MB)under UV-light irradiation can be attributed to the highly reactive facets exposed and more efficient separation of photogenerated electron-hole pairs.(4)CeO2/g-C3N4/ZnO ternary nanocomposites are obtained by CeO2/g-C3N4 nanosheets decorated with ZnO nanoparticles.Ternary composites not only enhance the stability of the catalyst but also restain the composite risk of photon-generated carrier.