Synthesis Of Ceria-based Materials And Its Performance In Photocatalytic Removal Of Nitric Oxide

Large-scale nitrogen oxides in industrial exhaust and automobile engine exhaust gases will cause an injury to the human body,and the greater danger is that it can form acid rain and photochemical smog.Therefore,the development of efficient denitrification catalyst to remove nitrogen oxides,curb the generation of haze,develop green recycling economy,and constructe the coordinated development between the environment and economy have been urgent.In this paper,we selected the biological tissue with rich and graded porous structure as the template,and obtained the biomimetic nano-photocatalytic materials with different structures by the induction of biological macromolecules.The key role of oxygen vacancy in guided light reduction was studied.The intrinsic relationship between the microstructure of the photocatalytic material-oxygen vacancy concentration-guided light reduction performance was revealed.Design of bionic nano-composite photocatalytic materials was guided by designing comparative experiments.Using different biological template and pretreatment method,regulating and cerium oxide nanoparticles composite carbon material,to build a simulated light reduction removal of exhaust gas reaction device.The effects of biomimetic graded porous structure on the reduction rate of nitrogen oxide and the reaction product were investigated by using the catalytic materials to simulate the industrial waste gas at different temperatures,different light intensities and different airspeed.In this paper,bionic nano-CeO₂ / graphene photocatalyst was prepared by using fresh bean sprouts,spirulina and rape stem as the biological template.Under the conditions of calcination temperature of 800 °C and calcination rate of 2 °C / min,the biological template with micro-morphology was precisely replicated by biomimetic CeO₂ / graphene nano-catalyst.It could be seen that after being characterized by fluorescence microscopy,X-ray diffraction,Raman,nitrogen adsorption desorption,electron microscopy and ultraviolet diffuse scattering,the pore structure and the grain size and the grain size of CeO₂ / graphene photocatalysts were more uniform and smaller which have been used to reproduce the high porosity.And the material inherited the high porosity,oversize surface area and easy to control micro-morphology of rapeseed stem template,which effectively enhanced the ability of the prepared nano-photocatalyst to capture visiblelight and significantly improved.The photocatalytic activity of the material provides a good catalytic environment for the subsequent photocatalytic denitrification.The optimum conditions for the photocatalytic degradation of nitrogen oxides were investigated by experiments.The calcination temperature of the CeO₂ / graphene was 800 °C which using rape stems as the best biological template for the nano-photocatalyst.and the calcination rate is 2 ° C / min,the catalyst was filled with6 m L,the concentration of NO was 600 ppm,the ammonia concentration was 600 ppm,the nitrogen gas was the carrier gas,the reaction temperature was 140 ° C and the space velocity was 1000 h-1.After the experiment,the catalytic removal efficiency of NO reached 87%.