Research On Preparation And Photo-catalytic Capability Of Nano Zinc Oxid By Sol-Gel Process

ZnO is used as a new type of wide bandgap semiconductor materials.Its wide band gap is3.37?eV and exciton binding energy is 60?meV at room temperature. Compared with ordinary ZnO, the characteristics of Nano-ZnO is quantum size effect, surface effect and macroscopic quantum tunnel effect and so on. These characteristics made it show excellent special performance on the light, electricity, magnetic, chemical, etc. ZnO is a new type of inorganic function semiconductor photocatalytic materials, it has been widely used in the field of photocatalysis. Now has many research on photocatalytic degradation of organic wastewater,but has rarely reported about the oil denitrification with ZnO.This article prepared nano-ZnO powder by sol-gel method. Study the optimum process conditions of preparation technology and the effect of doping ions on the properties of nano-ZnO structure and photocatalytic. And the pyridine as the goal of simulate oil degradation object, inspected the photocatalytic performance of the nanoparticle ZnO.(1) The experiment has prepared nano-ZnO powder by sol-gel method. When the reaction temperature is 70?℃, the dosage of solvent is 50?ml,we can get a uniform and stable sol. When the drying temperature is 80?℃, we can get a colorless transparent gel.We can get the white powder of ZnO when the calcination temperature is 600.This ZnO with has good photocatalytic performance. Under the optimum technological conditions of pure ZnO powder average grain size is about 41 nm.When the catalyst addition amount is 1?g/L, the photocatalytic time is 3?h, the denitrification rate of simulate oil is 24.75%.(2) The nano-ZnO powder was doped with different(Fe、Cu、Co、La、Ce、Ag) ion by sol-gel method. Fe doping can make the grain size of nano-ZnO powder decreased significantly, dispersed more uniform, photocatalytic performance is greatly increased. When the best doping concentration was 0.8%, the catalyst amount is 1?g/L, the photocatalytic time is 3?h, the denitrification rate of simulate oil is 87.68%. Cu doping did not make the photocatalytic properties of nano-ZnO improve significantly. When the best doping concentration was 3%, the catalyst amount was 1?g/L, the photocatalytic time is 3?h, the denitrification rate of simulate oil is 48.6%. Co doping can make the grain size of nano-ZnO powder smaller and the light absorption edge occurs obvious red shift. When the best doping concentration was 3%, the catalyst amount was 1?g/L, the photocatalytic time is 3?h, the denitrification rate of simulate oil is 62.28%. La doping can make the grain size of nano-ZnOpowder decreased significantly and the light absorption edge occurs slight blue shift.When the best doping concentration was 2%, the catalyst amount was 2?g/L, the photocatalytic time is 3.5?h, the denitrification rate of simulate oil is 65.42%. Ce doping can make the grain size of nano-ZnO powder slightly smaller, but the cerium ion is not completely mixed with ZnO lattice. Some exist in the surface of ZnO by CeO2. When the best doping concentration was 2%, the catalyst amount was 2?g/L, the photocatalytic time is 3.5?h,the denitrification rate of simulate oil is 68.62%. Ag doping has scarcely effect on the grain size of nano-ZnO powder, some elemental Ag exist in the surface of ZnO. When the best doping concentration was 1%, the catalyst amount was 1g/L, the photocatalytic time is 3h, the denitrification rate of simulate oil is 89.42%.