Study On Preparation Of Zinc Oxide Composite Piezoelectric Material And Its Removal Performance Of Organic Pollutants In Water

Zinc oxide（ZnO）,as a nanomaterial with easy preparation and good catalytic properties,it has great potential in the field of catalysis.graphene oxide（GO）has excellent physical and chemical properties,and GO has good hydrophilicity,it can adjust the electrical properties of zinc oxide through this kind of oxygen-containing groups to optimize its catalytic performance.Diatomaceous earth（DE）is non-toxic and odorless,with a large surface area and excellent adsorption capacity.In this paper,ZnO/GO composite piezoelectric materials and ZnO/CuO/DE composite piezoelectric materials were prepared,and the catalytic degradation performance of ZnO/GO composite piezoelectric materials on organophosphorus insecticide,as well as the purification and characterization of the degradation products were studied.Piezoelectric degradation properties of ZnO/CuO/DE composite piezoelectric materials for methylene blue and tetracycline hydrochloride.The main research results are as follows:（1）ZnO/GO composite piezoelectric materials were successfully prepared using zinc acetate dihydrate and GO as raw materials.A series of structural characterization and morphology experiments of ZnO/GO composite piezoelectric materials were carried out.It was found that ZnO was uniformly deposited on graphene oxide with a typical hexagonal prism-like rod-like structure.The graphene is of uniform thickness and thin film shape.（2）ZnO/GO composite piezoelectric materials were used for catalytic degradation of organophosphorus insecticide.The experimental results show that the maximum degradation rate is 74.2%when the dosage of ZnO/GO composite piezoelectric material is 0.0037g/ml,the degradation time is 120min and the PH value is 7.According to the results of EDS mapping of degraded ZnO/GO,there is no P and S adhesion,and it is presumed that there is no adsorption,which is mainly catalysis.By radical quenching experiment,t-BuOH and BQ were selected to quench·OH and·O2-radicals,respectively.It was found that t-BuOH and BQ had significant inhibition on the degradation of thionophos,and it was concluded that·OH and·O2-radicals were generated in the degradation process.Finally,the degradation products were purified and analyzed by nuclear magnetic spectrum.The degradation products were mainly p-nitro-m-cresol.（3）ZnO/CuO/DE composite piezoelectric materials were synthesized using ZnO/CuO and purified DE as raw materials.A series of structural characterization and morphology tests were carried out on ZnO/CuO/DE composite piezoelectric materials.It is found that ZnO/CuO has been successfully synthesized,zinc oxide has a rod-like structure,copper oxide has a sheet structure,and the two are evenly loaded together.Diatomite is a disk with many holes,and ZnO/CuO is evenly loaded on the diatomite.All three keep their typical structure unchanged.（4）ZnO/CuO/DE composite piezoelectric material was used for the piezoelectric degradation of methylene blue and tetracycline hydrochloride.The experimental results show that when the ratio of ZnO/CuO/DE composite piezoelectric material is 1:2,the content is 0.001g/ml,and the degradation time is 210min,the highest removal rates are99.1%and 97.9%,respectively.It is found that ZnO/CuO/DE composite piezoelectric material can cycle for methylene blue up to 5 times and tetracycline hydrochloride up to 4 times.By radical quenching experiment,t-BuOH,EDTA-2Na and BQ are selected to quench·OH,holes and·O₂^-radicals respectively,and it is found that t-BuOH,EDTA-2Na and BQ have obvious inhibitory effect on degradation of methylene blue and tetra ycline hydrochloride,thus it is concluded that holes are generated in the degradation process·OH and·O₂^-radicals,Finally,the corresponding piezoelectric catalytic degradation mechanism was derived.