Preparation Of Fly Ash Cenospheres Composite Photocatalysts And Study On Its Photocatlytic Degradation On Tetracycline

The extensive use of antibiotic wastewater makes more and more antibiotic residues left into the external environment,which brings serious harms to humans health and ecological balance.Antibiotic treatment of wastewater has attracted the attention of many scholarsr,due to the traditional sewage treatment techniques are limited.Advanced oxidation technology can degrade persistent refractory organics effectively,semiconductor photocatalytic technology is one of the most promising one.However,in the practical application,the photocatalyst has the problem that the photocatalyst is easy to be compounded and the catalyst is difficult to recover effectively,which has restricts the application of photocatalytic technology.In this paper,we introduce floating fly ash as a carrier-supported photocatalyst,it can use the formation of heterogeneous structures to suppress the composite of semiconductor photocatalyst photogenerated carriers effectively.And the manufacture of floating fly ash can achieve the effective recovery of photocatalyst,it will not cause secondary pollution of the photocatalyst.The main research results of this paper are as follows:1.Preparation of composite photocatalyst ZnWO₄/FACs and study on its photocatalytic activity.Using hydrothermal method synthesizes the ZnWO₄-supported FACs composite photocatalyst in one step.Using characterization methods such as XRD,SEM,FI-IR,UV-vis,to characterize the structure,morphology and optical properties of the composite photocatalyst.The results show that,when the mass ratio of fly ash floating beads and ZnWO₄ is 3: 1,the morphology,structure,and crystal are the best.ZnWO₄ is in the form of rice grains,about 20 nm in length,10 nm in diameter,dispersed on the surface of FACs uniformly.Using tetracycline hydrochloride as the search sample of target solution,photodegradation activity in the ultraviolet light,under the optimum conditions,light it 90 minutes,the degradation rate reaches 93%,and the photocatalytic activity is excellent.2.Preparation of PoPD-sensitized ZnWO₄ / FACs composite photocatalyst and its study on photodegradation of tetracyclic hydrochloride.The PoPD sensitized ZnWO₄ / FACs composite photocatalyst was prepared by two steps of hydrothermal synthesis and UV irradiation.According to the representation of the crystal structure,morphology,morphology and optical properties of the composites,the results show that,after ZnWO₄ / FACs heterojunctions were added to PoPD,PoPD was linked to the ZnWO₄ rod material that is on the surface of fly ash,and finally formed a snow-like structure,PoPD nanoparticles are about 20-30 nm in average,which deposited on the surface of the ZnWO₄ rod-like structure.Compared to the bandgap energy?3.09eV?of ZnWO₄,the bandgap energy of PoPD / ZnWO₄ / FACs composites was 2.69 eV.The efficiency of PoPD / ZnWO₄ / FACs composites was 76.72% under visible light conditions,and the ratio of PoPD / ZnWO₄ / FACs and kinetic reaction rate constant is 0.1021 min-1.3.Preparation of Bi2MoO₆ / FACs composite photocatalyst and study on Its photocatalytic activity.The Bi2MoO₆ / FACs composite photocatalytic materials were successfully prepared by one-step hydrothermal synthesis using SDBS as the surfactant.The structure,morphology and optical properties of the composite photocatalyst were characterized by a variety of characterization methods.The results show that,Bi2MoO₆ nanomaterials are uniform in particle size,about 1.2um in size,with a flower structure,load on FACs uniformly.Compared to the bandgap energy?2.7eV?of Bi2MoO₆,the adsorption properties of Bi2MoO₆ special flower structure,the size effect of Bi2MoO₆ / FACs band gap can be reduced to 2.17 eV,Under the visible light irradiation about 90 min,the degradation efficiency of tetracycline hydrochloride was almost 81%.